İSTANBUL TECHNICAL UNIVERSITY  GRADUATE SCHOOL OF SCIENCE

ENGINEERING AND TECHNOLOGY

NEW FUNCTIONAL POLYOLS FOR POLYURETHANES

Ph.D. THESIS

Başar YILDIZ

Department of Polymer Science and Technology

Polymer Science and Technology Programme

MARCH 2016
İSTANBUL TECHNICAL UNIVERSITY  GRADUATE SCHOOL OF SCIENCE
ENGINEERING AND TECHNOLOGY

NEW FUNCTIONAL POLYOLS FOR POLYURETHANES

Ph.D. THESIS

Başar YILDIZ
(515052013)

Department of Polymer Science and Technology

Polymer Science and Technology Programme

Thesis Advisor: Prof. Dr. Ahmet AKAR

MARCH 2016
İSTANBUL TEKNİK ÜNİVERSİTESİ  FEN BİLİMLERİ ENSTİTÜSÜ

POLİÜRETANLAR İÇİN YENİ FONKSİYONEL POLİOLLER

DOKTORA TEZİ

Başar YILDIZ
(515052013)

Polimer Bilim ve Teknolojisi Anabilim Dalı

Polimer Bilim ve Teknolojisi Programı

Tez Danışmanı: Prof. Dr. Ahmet AKAR

MART 2016
Başar Yıldız, a Ph.D. student of İTU Graduate School of Science Engineering and
Technology student ID 515052013, successfully defended the thesis entitled “NEW
FUNCTIONAL POLYOLS FOR POLYURETHANES”, which he prepared after
fulfilling the requirements specified in the associated legislations, before the jury
whose signatures are below.

Thesis Advisor : Prof. Dr. Ahmet AKAR ..............................

İstanbul Technical University

Jury Members : Prof. Dr. İ. Ersin SERHATLI .............................

İstanbul Technical University

Prof. Dr. Ayşen ÖNEN ..............................

İstanbul Technical University

Prof. Dr. Tarık EREN ..............................

Yıldız Technical University

Prof. Dr. Atilla GÜNGÖR ..............................

Marmara University

Date of Submission : 15 February 2016

Date of Defense : 04 March 2016

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To my mother Saime YILDIZ and my lovely family,

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FOREWORD

I would like to express my deep appreciation and thanks for my advisor Prof. Dr.
Ahmet Akar for his endless support and for giving me the opportunity to learn about
the field of flame retardants.
I would like to thank Tükek family, my colleagues from Flokser Tekstil ve Tic. Aş;
Gökay Gürel, Erhan Mendi, Lale Şen Çetin for helping at experiments and
characterization parts.
Last but not least, I cannot thank enough my wife, as none of this would have been
possible without her constant support.

February 2016 Başar YILDIZ

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TABLE OF CONTENTS

Page

Polyurethane ........................................................................................................... 3
2.1.1 Isocyanates .................................................................................................. 4
2.1.2 Polyols ......................................................................................................... 5
2.1.2.1 Polyether polyol ................................................................................... 7
2.1.2.2 Polyester polyol .................................................................................... 7
Polymer containing polyester polyol ........................................................... 9
2.1.2.3 Acrylic polyol..................................................................................... 10
2.1.2.4 Polysiloxane polyol ............................................................................ 11
2.1.2.5 Polybutadiene polyol .......................................................................... 12
2.1.2.6 Chain extender ................................................................................... 13
2.1.2.7 Reactions of isocyanates .................................................................... 16
2.1.2.8 Catalyst ............................................................................................... 17
Ketonic Resins ..................................................................................................... 19
2.2.1 Modification of ketonic resin .................................................................... 21
2.2.1.1 Modification of ketonic resin during the preparation (in situ
modifications) ................................................................................................ 21
2.2.1.2 Modification of ketonic resin after preparation via their functional
groups ............................................................................................................. 23
2.2.1.3 Kabachnik-Fields reaction ................................................................. 23
Flame Retardants .................................................................................................. 25
2.3.1 General approaches of flame retardant for polymers ................................ 25
2.3.1.1 Gas phase flame retardants (Examples: Halogen, Phosphorus) ......... 26
2.3.1.2 Endothermic flame retardants (Examples: Metal Hydroxides,
Carbonates) .................................................................................................... 26
2.3.1.3 Char forming flame retardants (Examples: Intumescents,
Nanocomposites) ............................................................................................ 26
2.3.2 Phosphorus flame retardants ..................................................................... 27
2.3.2.1 Mechanism of the effect of phosphorus-based fire retardants ........... 27
2.3.3 Fire resistance polyurethanes .................................................................... 28
2.3.3.1 Halogenated fire retardants ................................................................ 29
2.3.3.2 Organic phosphorus compounds ........................................................ 29

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 2.3.3.3 Organic phosphorus and halogen compounds as fire retardants ........ 29
2.3.3.4 Additive type flame retardants ........................................................... 30
2.3.3.5 Reactive flame retardant..................................................................... 31

Materials ............................................................................................................... 39
Measurments ........................................................................................................ 40
3.2.1 Evaluation of flame retardancy ................................................................. 42
3.2.1.1 Thermal gravimetry analysis (TGA) .................................................. 42
3.2.1.2 UL 94 test ........................................................................................... 42
3.2.1.3 Oxygen index test ............................................................................... 43
Synthesis Of Styrene Graft Polyester Polyol ....................................................... 43
3.3.1 Synthesis of saturated polyester polyol ..................................................... 43
3.3.2 Styrene grafting saturated polyester polyol ............................................... 43
3.3.3 Synthesis of unsaturated polyester polyol ................................................. 44
3.3.4 Styrene grafting unsaturated poliester polyol............................................ 44
Synthesis Of Ketonic Resins ................................................................................ 45
3.4.1 Mek-formaldehyde resin ........................................................................... 45
3.4.2 Cyanuric acid-formaldehyde reaction ....................................................... 45
3.4.3 Acetophenone-formaldehyde resin ........................................................... 45
3.4.4 Acetophenone-formaldehyde-dichloroacetophenone resin ....................... 46
3.4.5 Acetophenone-formaldehyde-dichloroacetophenone-cyanuric acid ......... 47
3.4.6 MEK-formaldehyde-melamine reactions (a) ............................................ 47
3.4.7 MEK- formaldehyde –melamine reactions (b).......................................... 48
3.4.8 MEK-formaldehyde-cyanuric Acid........................................................... 48
3.4.9 Synthesis of cyclohexanone-formaldehyde resin (CF-R) ......................... 48
3.4.10 Cyanuric acid - formaldehyde - diethanol amine .................................... 49
3.4.11 Modification of ketonic resins with ethanol amine/DEP and DPP ......... 50
Synthesis THEIC-Tris (2-chloroethyl) Phosphite ................................................ 51
Synthesis THEIC-TCPP ....................................................................................... 52
3.6.1 Preparation of the polyurethane rigid foam............................................... 53
Vinyl Phosphonic Acid Dimethyl Ester Grafting Onto Unsaturated Polyester
Polyol .................................................................................................... 54
Other Mixture Polyols .......................................................................................... 54
3.8.1 Dopo - maleic anhydride reaction ............................................................. 54
3.8.2 Oxazolidine-diethyl phosphite reaction .................................................... 55
Synthesize Biobased Synthetic Leather ............................................................... 56

Polyurethane From Styrene Grafted Polyols ........................................................ 57

4.1.1 Synthesis of polyester polyol .................................................................... 57
4.1.2 Grafting styrene on saturated polyester polyol ......................................... 58
4.1.3 Synthesize of unsaturated polyester polyol ............................................... 59
4.1.4 Styrene grafting on unsaturated polyester polyol ...................................... 60
Synthesis of Fire Retardant Modified Ketonic Resins ......................................... 62
4.2.1 Kabachnik-Fields reaction of cyclohexanone- formaldehyde resin (CF-
Resin) with diethyl phosphite (DEP) and ethanolamine .................................... 62
4.2.2 Kabachnik-Fields reaction of methyl ethyl ketone-formaldehyde resin
(MEKF-Resin) with DEP and ethanolamine ...................................................... 65
4.2.3 Kabachnik-Fields reaction of acetophenone-formaldehyde resin (AF-
Resin) with DEP and ethanolamine ................................................................... 68

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 4.2.4 Fire retardant polyurethane production using fire retardand modified
ketonic resins containing halogen, phosphorous and nitrogen .......................... 75
4.2.4.1 Polyuretane produced using fire retardant modified CF-resin and
MEK-F resin .................................................................................................. 75
4.2.5 Polyurethane produced using modified AF-resin and DiCLAF- resin ..... 77
Fire Resistant Polyurethane Using THEIC-Tris (2-chloroethyl) Phosphite Products
.............................................................................................................. 80
Fire Resistant Polyurethane From THEIC-TCPP Products ................................. 84
4.4.1 Formation of THEIC-TCPP products ....................................................... 84
4.4.2 Characterization of FR obtained from THEIC and TCPP ........................ 86
4.4.3 The flame retardant effect of FR products ................................................ 90
4.4.3.1 Structure of the polyurethane containing flame retardant (FR) ......... 90
4.4.3.2 The flame retardant effect of FR type and amount ............................ 91
4.4.3.3 Further studies on fire resistance polyurethane foam production ...... 92
4.4.3.4 TGA results of THEIC-TCPP products ............................................. 93
Fire Resistant Polyurethanes From Mixture of Polyols ....................................... 94
Fire Resistant Polyurethanes From Vinyl Phosphonate Grafted Polyols ............ 96
Synthesis of Synthetic Leather Polyurethane From Biobased Polyol .................. 98

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ABBREVIATIONS

PU (PUR) : Polyurethane
PTMG : Polytetramethylene Glycol
MDI : 4,4'-Methylene Diphenyl Diisocyanate
PMDI : Polymeric MDI
TDI : Toluene Diisocyanate
UV : Ultraviolet
PPG : Polypropylene Glycol
TPU : Thermoplastic Polyurethane
BDO : 1,4- Butanediol
MMA : Methylmethacrylate
PDMS : Polydimethylsiloxane
FR : Flame Retardant
DMPP : Dimethyl Phosphonate
PIR : Polyısocyanurate
DPP : Diphenyl Phosphite
VPADME : Vinyl Phosphonic Acid Dimethylester
TCPP : Tris (1-Chloro-2 Propyl) Phosphate
LOI : Limiting Oxygen Index
MEK : Methyl Ethyl Ketone
DMF : Dimethylformamide
CF-R : Cyclohexanone-Formaldehyde Resin
MEKF-R : Methyl Ethyl Ketone-Formaldehyde Resin
DEP : Diethyl Phosphite
AF-R : Acetophenone-Foramladehyde Resin
THEIC : Tris (hydroxyethyl) isocyanurate
AA : Adipic Acid
DEG : Diethylene Glycol
PES : Polyester
HBA : 4-Hydroxybutyl Acrylate
DOPO : 9,10-Dihydro-9-Oxy-10-Phosphaphenanthrene-10-Oxide
DMSO : Dimethyl Sulfoxide
FTIR : Fourier Transform Infrared Spectroscopy
1H NMR : Proton Nuclear Magnetic Resonance
C-13 NMR : Carbon-13 Nuclear Magnetic Resonance
P-31 NMR : Phosphorus-31 Nuclear Magnetic Resonance
EA : Ethanolamine
DICAFR : Acetophenone-2,4-Dicholoroacetophenone-Formaldehyde Resin

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LIST OF TABLES

Page

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LIST OF FIGURES

Page

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 NEW FUNCTIONAL POLYOLS FOR POLYURETHANES

SUMMARY

In this work, different polyols have been either synthesized or used to for three
fundamental industrial application areas. These application areas are shoe sole, rigid
foam (isolation) and artificial leather, respectively.
First, low density requirements in shoe sole applications have been solved by
producing polystyrene dispersions in polyester polyol and then styrene graft
unsaturated polyols have been utilized to meet the needs in industry. With the help of
these dispersions shoe soles with higher amount of open cells have been obtained. In
this respect, products with lower density are obtained and comfort and cost advantages
provided for end users. Styrene grafted polyester polyols were produced by adding
styrene and dibenzoil peroxide into polyol and mixed and heated up to 130-150oC to
get styrene grafted polyol. Both saturated and unsaturated polyester polyols were
synthesized and used for styrene grafting polymerization. The effect of polymerization
temperature, dibenzoil peroxide concentration and styrene concentration were
examined and optimum conditions were set up for industrial application. The final
polyol product was vacuum distilled to remove residue styrene monomer. Other
initiators such as AIBN and t-butyl hydro peroxide were also tried. Highest styrene
grafting efficiency was about 12 wt. % based on polyol. The structure of the styrene
grafted polyols were proved by using FTIR. Their physical and chemical properties
such as viscosity, hydroxyl value, acid value, water content were determined. The
polyurethane foam produced from these styrene grafted polyols has better stability and
much lower shrinkage value depending on the amount of styrene grafted.
Second application; trichloropropyl phosphate (TCPP) has been widely used as fire
retardant in rigid foam applications of polyurethane. However, toxic TCCP migrates
out of the foam in time and toxic TCPP accumulate in the atmosphere and
unfortunately the fire retardant property of the foam decreases. Due to these
disadvantages of TCPP, some new alternative fire retardant agents have been
synthesized by reacting TCPP with trihydroxyethyl isocyanurate (THEIC). Mole ratio
of TCPP: THEIC were 1:1, 2:1, 3:1, and 5:1 respectively and the physical and chemical
properties such as hydroxyl value, FTIR, NMR, TGA, GPC and viscosity of the
produced fire retardant compounds were examined. The formed transesterification
products have higher molecular weight and contain active primary hydroxyl group.
Obtained new products are fire retardants compounds and can be used in the place of
TCPP in fire retardant polyurethane formulations. These new products would be
chemically bonded to polyurethane foam since they contain active primary OH groups.
The covalent bonding eliminates the problem of migration and volatility of the fire
retardant compounds. These produced fire retardant compounds were added into
polyol component in the range of 5-23 wt. % of polyol and their fire retardant
properties were compared using TGA, LOI and UL94 test methods. The fire retardant

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efficiency of the new non-volatile and reactive compounds were about the same of
TCPP.
Third, similar studies were carried out for the synthesis of transesterification reaction
products between THEIC and tri (2-chloroethyl) phosphite. The formed products were
added into polymix component in the range of 5-20wt% of polymix and the fire
retardant properties of produced rigid polyurethane foams were compared using TGA,
LOI, and UL94 test methods. 20 different polyurethane formulation were prepared and
the fire retardant effect of the new nonvolatile reaction products were compared and
found that their effects were about the same of TCPP.
Fourth, for halogen free and non-toxic fire retardant compounds, modified ketone
resins have been synthesized and used as an alternative fire retardant.
The utilized resins were methyl ethyl ketone-formaldehyde resin (MEKF-Resin),
cyclohexanone-formaldehyde resin (CF-Resin) and acetophenone-formaldehyde resin
(AF-Resin) and they were modified with a mixture of diethylphosphite and ethanol
amine and a mixture of diphenylphosphite and ethanol amine by using the Kabachnik-
Fields reaction. Increasing reaction time and addition of catalyst such as magnesium
perchlorate increase the conversion of carbonyl groups of the ketonic resin. However,
conversion yield of carbonyl groups of ketonic resins were in the range of 60-85% thus
the modified resins would have phosphorous in the range of 2-6%. The physical
properties such as solubility in organic solvents and melting point of modified resins
were drastically different than corresponding base ketonic resins. The structures of
modified ketonic resins were elucidated by using FTIR, 1H-NMR, 13C-NMR and
31P-NMR spectroscopy and microanalysis. These modified ketonic resins were added
into polyol component of the rigid polyurethane foam in the range of 5-25% and fire
resistant properties of the foam products were determined using TGA, LOI and UL94
test methods. Polyurethane foams containing about 10 wt. % modified MEKF-Resin,
modified CF-Resin and modified AF-Resin showed considerably good fire retardant
effect.
Fifth, with the help of the knowledge gained from styrene grafting to polyester polyol
grafting of dimethyl vinyl phosphonate to polyol has been studied to develop new
polyester polyols with fire retardant property. The effect of polymerization time, the
amount of initiator and temperature was studied. The viscosity, hydroxyl value of
dimethyl vinyl phosphonate grafted polyol determined and used as polyol component
in rigid polyurethane production. This developed polyester polyol containing about
20% dimethyl vinyl phosphonate enhanced the fire retardant property of the
polyurethane foam and achieved a 9 cm fire length value in the horizontal test chamber
in the UL 94 test.
Sixth, furthermore different additional new polyols have been synthesized and
investigated for their fire retardant effect in the end product of rigid polyurethane foam.
The Mannich reaction products of isocyanuric acid, diethanolamine and formaldehyde,
and trimethylol isocyanurate were among synthesized compounds. Additionally, the
reaction product of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)
with maleic anhydride and melamine modified ketone resin have been synthesized.
However, the synthesis of these type of compounds has not been continued without
any further research attempts due to low fire retardant property and/or high cost.
Seventh, using bio-based polyols. Nowadays, bio-based product development is one
of trend research topic. The world tends to favor the usage of sustainable resources
instead of petroleum. International companies make investments and request products.
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In this respect, bio-polyol has been supplied from Croda Corporation. By using this
polyol, toxic dimethylformamide free polyurethane artificial leather has been
synthesized. Dimethyl sulfoxide and toluene have been used as solvent. The obtained
product was a bio-based (51% Bio), dimethylformamide free polyurethane artificial
leather and its physical properties were similar to conventional polyurethane artificial
leather prepared under similar conditions.

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 POLİÜRETANLAR İÇİN YENİ FONKSİYONEL POLİOLLER

ÖZET

Bu çalışmada, üç farklı temel uygulama alanı için çeşitli polioller sentezlenmiş veya
kullanılmıştır. Bu uygulamalar sırasıyla, ayakkabı tabanı, sert köpük(yalıtım için) ve
suni deridir.
Ayakkabı tabanı uygulamalarındaki İlk düşük yoğunluk talebi, poliester poliolde
polistiren dispersiyonu hazırlayarak çözülmüş ve sonra stiren graft edilmiş doymamış
poliol kullanılarak endüstrinin ihtiyacı karşılanmıştır. Bu dispersiyonların yardımıyla,
yüksek miktarda açık hücreler içeren ayakkabı tabanlığı elde edilmiştir. Nu şekilde,
düşük yoğunluklu ürünler elde edilirken konfor ve maliyet avantajları oluşmuştur.
Stiren graftlanmış poliester poliol, poliolün içine stiren ve benzoil peroksidin
eklenmesi, karıştırılması ve sıcaklığın 130-150oC çıkarılmasıyla elde edilmiştir.
Doymuş ve doymamış poliesterlerin herikiside sentezlenmiş ve stirenin graft
edilmesinde kullanılmıştır. Polimerleşme sıcaklığı, benzoil peroksit konsantrasyonu
ve stiren konsantrasyonu etkisi araştırılmış ve endüstriyel uygulama için optimum
şartlar tespit edilmiştir. Son poliol ürünü, içende kalan stiren monomerini
uzaklaştırmak için vakum damıtılması yapılmıştır. Ulaşılan en yüksek stiren graft
etkinlik değeri poliol ağırlığının %12’si olmuştur. Ürünün viskozite, hidroksil sayısı,
asit sayısı ve su içeriği gibi fiziksel ve kimyasal özellikleri tespit edilmiştir.
Bu stiren graft edilmiş poliolden üretilen poliüretan köpüğün stabilitesi graftlanmış
stiren miktarına bağlı olarak daha iyi ve büzülme değerine daha azdır.
İkinci uygulama, trikloropropil fosfat (TCPP), alev geciktirici olarak rijit poliüretan
uygulamalarında çok yaygın kullanılmaktadır. Fakat toksik olan TCPP, zamanla
migrasyona uğrar ve atmosferde birikir ve maalesef köpüğün alev geciktirici özelliği
azalır. TCPP nin bu olumsuzlukları nedeniyle, bazı yeni alternatif alev geciktiriciler,
TCPP nin trihidroksietil izosiyanürat (THEIC) ile reaksiyonu ile sentezlenmiştir.
TCPP:THEIC mol oranları sırasıyla 1:1, 2:1, 3:1, ve 5:1 alındı ve üretilen alev
geciktirici ürünlerin hidroksil sayısı, FTIR, NMR, TGA, GPC and viskozitesi gibi
fiziksel ve kimyasal özellikleri iclenmiştir. Oluşan transesterleşme ürünleri daha
yüksek mol ağırlığına sahip olup aktif primer hidroksil grubu içerir. Ele geçirilen yeni
ürünler alev geciktirici bileşiklerdir ve alev geciktirici poliüretan formülasyonlarında,
TCPP yerine kullanılabilir. Bu yeni ürünler aktif primer hidroksil grubu içerdiği için
poliüretana kimyasal olarak bağlıdır. Kovalent bağ, alev geciktirici bileşiklerin
uçuculuk ve migrasyon problemlerini ortadan kaldırır. Bu üretilen alev geciktirici
bileşikler poliol komponenti içine, poliolün ağırlıkça % 5-23 arasında eklenmiştir ve
alev geciktirici özellikleri TGA, LOI ve UL94 test yöntemleri kullanarak mukayese
edilmiştir. Bu yeni uçucu olmayan ve reaktif bileşiklerin alev geciktirici bileşikleri
alev geciktirici etkinliği TCPP’ye aynıdır.
Üçüncü çalışmada, benzer çalışmalar THEIC ve tri(2kloroetil) posfit arasındaki
transesterleşme reaksiyonu ile sentezlenecek ürünler için gerçekleştirilmiştir. Oluşan
ürünler polimiks komponenti içine, polimiks’in %5-20 kadar eklenir ve oluşan
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poliüretan köpüklerin alev geciktirici özellikleri TGA,LOI ve UL94 test yöntemleri
kullanarak mukayese edilmiştir. 20 farklı poliüretan formülasyonu hazırlanmış ve alev
geciktirici etkileri incelenmiş ve etkilerinin TCPP ile aynı düzeyde olduğu
bulunmuştur.
Dördüncüsü, halojen içermeyen ve toksik olmayan alev geciktirici bileşikler olarak
modifiye ketonik reçineler sentezlenmiş ve alternatif alev geciktirici olarak
kullanılmıştır.
Kullanılan reçineler, metil etil keton- formaldehit reçinesi (MEKF-Resin),
siklohekzanon-formaldehit reçinesi (CF-Resin), asetofenon-formaldehit reçinesi (AF-
Resin) ve bu reçineler dietil fosfit ve etanolamin karışımı ve difenilfosfit ve etanol
amin karışımı ile Kabachnik-Fields reaksiyonu kullanılarak modifiye edilmiştir. Artan
reaksiyon zamanı ve magnezyum perklorat gibi kataliz eklenmesi ketonik reçinenin
karbonil grubunun dönüşüm verimi arttırmıştır. Fakat, ketonik reçinenin karbonil
grubunun dönüşüm verimi %60-85 arasında kalmıştır ve böylece modifiye reçineler
%2-6 aralığında fosfor içerikli olmuştur. Modifikasye olmuş ketonik resin’in organik
çözücülerde çözünürlüğü ve erime sıcaklığı gibi fiziksel özellikleri, asıl reçinin
değerlerinden dramatik bir şekilde farklılaşmıştır. Modifiye ketonic reçinelerin
yapıları FTIR, 1H-NMR, 13C-NMR, and 31P-NMR spektroskopisi ve mikroanaliz
kullanarak aydınlatılmıştır. Bu modifiye ketonik reçineler, sert poliüretan
formülasyonunda kullanılan poliol komponenti içine %5-25 oranında katılmıştır ve
poliüretan köpük ürünlerinin alev geciktirici özellikleri TGA, LOI, ve UL94 test
yöntemleri kullanarak tayin edilmiştir. Yaklaşık %10 modifiye MEKF-Reçine,
modifiye CF-Reçine ve modifiye AF-Reçinesi içeren poliüretan köpükler oldukça iyi
alev geciktirici özellik göstermişlerdir.
Beşincisinde ise stiren graft yapımında kazanılan deneyim ile dimetil vinil fosfonat’ın
poliole graft yapılması alev geciktirici özellikli yeni poliester polioller geliştirilmesi
amacıyla çalışılmıştır. Polimerleşme zamanı,başlatıcı miktarı, ve sıcaklığın
polimerleşmeye etkisi çalışılmıştır. Dimetilvinil fosfonat graft edilmiş poliollerin
viskozitesi ve hidroksil değerleri tayin edilmiş ve poliol komponenti olarak rijit
poliüretan üretiminde kullanılmıştır. Yaklaşık %20 dimetil vinil fosfonat içeren bu
geliştirilmiş poliester poliol, poliüretan köpüğün alev geciktirici özelliğini iyileştirmiş
ve UL94 yatay test bölmesinde 9 cm lik alev uzunluğu değeri gerçekleştirmiştir.
Altıncı olarak, farklı yeni ek polioller sentezlenmiş ve poliüretan son üründe alev
geciktirici etkileri incelenmiştir. İzosiyanürik asit, dietanolamin ve formaldehit
arasındaki Mannich reaksiyon ürünü ve trimetiol izosiyanürat sentezlenen bileşikler
arasındadır. Buna ek olarak, melamin modifiye ketonik reçine, 9,10-dihidro-9-okza-
10-fosfafenantren-10-oksit (DOPO) ile maleik anhidrit reaksiyon ürünü
sentezlenmiştir. Fakat, düşük alev geciktirici özelliği ve/veya yüksek maliyeti
nedeniyle, bu tür bileşiklerin sentezine daha fazla araştırma denemeleri yapılmadan
devam edilmemiştir.
Yedincisi, biyo esaslı poliollerin kullanımı. Günümüzde, biyo esaslı ürün geliştirme,
araştırma konularındaki eğilimden birisidir. Dünya, petrol yerine yenilenebilir kaynak
kullanımını tercih etmeye meyillidir. Uluslararası firmalar yatırımlar yapmakta ve
ürünler talep etmektedir. Bu çerçevede, Croda firması biyo-poliol sunmaktadır. Bu
poliolü kullanarak, toksik dimetilformamid içermeyen poliüretan suni deri
sentezlenmiştir. Dimetilsülfoksit ve toluen solvent olarak kullanılmıştır. Elde edilen
ürün biyo-esaslı(%51), dimetilformamid içermeyen poliüretan suni deridir ve onun

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fiziksel özellikleri, aynı koşullarda hazırlanan bilinen poliüretan suni derinin
özelliklerine benzerdir.

xxxi
xxxii
 INTRODUCTION

Polyurethanes (PUs) are part of a very functional group of materials which are used in
a wide range of domestic and industrial applications. Polyurethanes are widely used in
many applications such as paints, artificial leather, foam mattresses, medical implants,
rollers, insulation rigid foam, electrical encapsulation, engineering components, shoe
soles, seals, and in the mining industry.

Polyurethanes are organic polymers that contain the urethane group in the structure. In
general, they are produced by the reaction of a polyol with a diisocyanate. Depending
on end use, the reaction may require the addition of additives such as chain extenders,
catalysts, and blowing agents. The entire process can be carried out in one step by
arrangement of the chemistry. Polyureas are similar in reaction to polyurethanes. They
are made from polyamides and not polyols. Instead of urethane groups, they contain
urea groups. Figure 1.1 illustrates the differences of the urethane and urea groups.

O O

HN O HN NH

R R R R

Urethane Urea

Figure 1.1 : Urethane and Urea Structure.

Polyurethane was first discovered by Otto Bayer and coworkers at I.G. Ferbenindustri,
Germany in 1937 (Oertel, 1985). The initial work was the reaction of aliphatic
isocyanate with a diamine to form polyurea which was infusible and hydrophilic.
Further research on this subject demonstrated the reaction of a glycol with an aliphatic
isocyanate to produce new materials with interesting properties. The industrial scale
production of PU started in 1940. A noticeable improvement in the elastomeric
properties PU was achieved in 1952, when polyisocyanate became commercially
available. In 1952–1954, Bayer developed different polyester–polyisocyanate system.
In 1958, Schollenberger of BF Goodrich introduced a new virtually crosslinked

1
thermoplastic PU elastomer. At approximately the same time, Dupont introduced a
Spandex fibre called Lycra, which is a PU based on polytetramethylene glycol
(PTMG), 4,4-diphenylmethylene diisocyanate (MDI) and ethylene diamine. With the
development of low-cost polyether polyols, PU coatings opened the door for
automotive applications. Formulations and processing techniques continuously
developed as one- and two-pack systems were developed. The PU coating industry has
entered a stage of stable progress and advanced technological exploitation. Today, PU
coatings can be found on many different materials, to improve their appearance and
lifespan. PU coatings give the demanded exterior high gloss, improved color retention,
improved scratch and corrosion resistance in automotive industry. Different types of
PU coatings are used in construction, where construction components are spray coated
to make them more durable against environmental deterioration (Kim, 2003).

The wide applicability of polyurethane is due to functionality in selection of

monomeric materials from a wide variety of macrodiols, diisocyanates and chain
extender. The chemistry involved in the synthesis of polyurethane is centered on the
isocyanate reactions (Szycher, 1999).

Recent trends in polyurethane are:

Renewable compounds, halogen free, non-toxic and smoke suppressant fire retardant
polyols.

The main aim of this work is to synthesize variety of polyurethanes by using different
special polyols with below properties;

Low density elastic and tough polyurethane for shoe sole;

Polyols for non-combustible and smoke depressed for rigid polyurethane;

Bio based polyurethane for synthetic leather;

Using these polyols polyurethane elastomers, microcellular elastomers, ıntegral skin

polyurethanes, rigid polyurethane foams will be synthesized. After these works
ındustrial trials and tests will also be carried out.

2
 THEORICAL PART

Polyurethane

Polyurethanes (PUs or PURs) are an extremely versatile class of polymers. A wide

variety of raw materials coupled with adaptable synthetic techniques allows the
polyurethane chemist to design useful materials for many applications with different
functions.

Table 2.1 lists commercially important usage categories for urethanes along with
examples of manufacturing methods and physical properties. All of the items shown
can be readily achieved by proper choice of starting materials, polymer design,
processing conditions, and application technique. While polyurethanes certainly have
limitations, it is arguable that no other class of polymers can match their collective
versatility, usefulness, and performance.

Urethane polymers are formed by reaction of polyisocyanates and polyols which create
the urethane chemical linkage. The general structure or bond that forms the basis of
this chemistry is the urethane linkage shown in Figure 2.1.Second level titles must be
bold and the first letter of each word in the title must be capital (i.e. 2.1 Process
Qualification Analysis).

Polyurethanes are of great significance in a large number of industrial applications.

For example they can be use in shoe sole, rigid foam (isolation) and artificial leather
industries. These include adhesives, elastomers and foams, as well as raw materials for
coatings.

O
R1 NH O R2

Basic urethane structure.

In Table 2.1 Types of polyurethane applications, their physical states and properties
and also their processing methods are summarised.

3
 Polyurethanes: Applications, properties and processing methods.
Applications Physical States and Properties Processing Methods

Foams Thermosets Open-cast molding

Elastomers Thermoplastics Fiber spinning
Coatings Amorphous or Blow molding
Adhesives/sealants/binders Microcrystalline Injection molding
Encapsulants Hard or soft Extrusion/pultrusion
Elastomeric fibers Transparent or opaque Reaction injection
Films High or low Tg Molding
Gels Aromatic or aliphatic Spraying/brushing/rolling
Composites Hydrophilic or Resin transfer molding
Microcellular elastomers Hydrophobic Rotational casting
Rubbers/millable gums 100% Solids/solvent Rotomolding
borne/water borne Thermoforming
Resilient or energy Compounding/vulcani-
Absorbing Zation
Polyester/polyether/ Compression molding
Polyacrylate Centrifugal molding

2.1.1 Isocyanates

Unlike polyethylene, which is the polymerization product of ethylene, polyurethane is

not the result of the polymerization of urethane. Urethane is a specific chemical bond
that comprises a very small percentage of the bonds of polyurethane.

There are several ways to categorize isocyanates. However, the broadest picture is
aromatic versus aliphatic. Aromatic MDI, PMDI, and TDI constitute by far the largest
worldwide volume of isocyanates manufactured. Two characteristics emerge with
these compounds. First, their aromaticity causes materials based on them to absorb
ultraviolet (UV) radiation, which triggers numerous oxidative side reactions in the
presence of atmospheric oxygen and water. These oxidation reactions form colored
quinoidal and other delocalized moieties which cause a discoloration to yellow or
brown. Discoloration is undesirable in most applications, but usually does not affect
bulk physical properties unless its extent is extreme. In coating applications, this
sensitivity to light is critical and can cause not only discoloration but also loss of
surface gloss, crazing, and many other problems. UV radiation can also penetrate a
larger percentage of the material’s thickness, affecting not only the surface, but the
bulk properties of the material as well, causing embrittlement, cracking, and peeling.
It is important to note that although aliphatic urethanes are dramatically less sensitive
to light than aromatic formulations, they are still susceptible to UV-induced
degradation and are extensively tested accordingly.

4
It is important to be aware of the chemical effects of isocyanates. The ratio of the
polyols and isocyanates will in part dictate both the physical and chemical properties
of the product. As a general rule, the isocyanates are hard segments that impart rigidity
to the polymer (Gillis, 1994). There are different types of isoctanates listed in Figure
2.2.

3 2 2' 3'
NCO NCO OCN CH2 NCO
4 1 1' 4'
CH2

4.4’ Dicyclohexylmethane diisocyanate

4.4’, 2,4’ and 2,2’ Methylene diphenyl diisocyanate
(MDI)

OCN
NCO NCO NCO NCO
CH2 CH2

Hexamethylene diisocyanate
n=1 4

Polymeric MDI (PMDI)

H3C CH3 CH3

1 NCO
OCN CH2 6
OCN 2
NCO 5 3
H 3C 4

Isophrone diisocyanate (IPDI) 2.4 and 2.6 diisocyanate

O (CH2)6NCO
NCO
N

OCN(CH2)6 N O

O (CH2)6NCO
NCO
Isocyanurate trimer of HDI
Naphtalane diisocyanate

Examples of commercially important isocyanates.

2.1.2 Polyols

The polyol takes part in defining properties of the finished polymer, including
flexibility, softness, low-temperature properties, and processing characteristics.

5
Figure 2.3 shows representations of common polyol types, distinguished by their
backbone structure. (Ionescu, 1998)

O
HO H

Polyethylene glycol Polyester polyol

(C2 polyether polyol)

O
H O H

Polycarbonate polyol
Polypropylene glycol
(C3 polyether polyol)

O
O
H C O
HO H O H

Polytetramethylene glycol Polycaprolactone polyol

C4 polyether polyol

H2N NH2
O

Polyacrylate polyol (Acrylic)

Amine terminated polyether
(ATPE)

Polybutadiene polyol

Common urethane-grade polyol types.

6
2.1.2.1 Polyether polyol

Polyether diols form a very important segment of the diols used in the manufacture of
polyurethanes. The normal route is by addition polymerization of the appropriate
monomeric epoxide.

The most important polyethers are polypropylene glycol (C3) and polytetramethylene
glycol (C4). The manufacturing route is given in Figure 2.4.
CH3
CH3

H2C CH O CH
Base catalyst
H C OH
O H2 n
H2C CH2 H2 H2
Lewis catalyst O C C
H2C CH2 H C C OH
H2 H2
O n

Manufacturing route of PPG and PTMEG.

Polyurethanes produced from polyether glycols are not as strong and tough as the
polyester-based polyurethanes, but they have far superior hydrolytic stability. The
standard polyol in this group is polytetramethylene glycol (PTMEG), which gives
compounds superior physical and mechanical properties to those produced with
polypropylene glycol (PPG). The PTMEG provides excellent mechanical properties
and very low abrasion loss.

2.1.2.2 Polyester polyol

There are three main classes of polyester polyols: (i) Linear or lightly branched
aliphatic or aromatic polyester polyols (mainly adipates or phtalates) with terminal
hydroxyl groups, (ii) Polycaprolactones and (iii) Polycarbonate polyols

Ester linkage have inherently better oil resistance but lower hydrolytic stability. The
classical-based polyester is made by the reaction of a dibasic acid diol with the
formation of a polyester and water, but the water has to be removed. The general
reaction equation is shown in Figure 2.5.
O R O
C C R1
+ HO OH H O C R C O R1 O H + H2O
OH OH
O O n

Dibasic acid Diol

Polyester polyol reaction.

7
Polyesters produce strong, tough, oil-resistant materials. The major drawback is
absence of hydrolysis resistance. The basic polyester polyols are prepared by the
reaction of a dibasic acid (usually adipic, sebacic, or phthalic acid) with a diol such as
ethylene glycol, 1,2-propylene glycol, and diethylene glycol.

The polyesterification conditions must be such that only hydroxyl groups form the
terminal groupings. The water of condensation formed must be removed to a level of
0.03% for production of good polyurethanes in the next step.

The molecular weight of polyester polyol is determined by the molar ratio of the
glycols and adipic acid. Closer the molar ratios to 1:1, higher the degree of
polymerization is maintained. The functionality of polyester polyol can be increased
by the introduction of triols such as glycerol or trimethylolpropane, which leads to
branching of the polyester backbone.

Polyester polyols for elastomeric applications are usually linear or slightly branched,
with the latter used mainly for fast curing shoe soling applications. The glycol selection
is a decision making between cost, ease of processing and the required level of physical
properties. For thermoplastic polyurethane (TPU) applications, adipates based on
ethlene glycol, 1,4-butane diol and 1,6-hexane diol are most commonly used

Polycaprolactam polyol is made by the opening of the caprolactam ring.Caprolactam

is also used in the production of nylon. Their structure appears to provide a degree of
protection from hydrolytic attack. They are formed by the reaction shown in Figure
2.6. Their hydrolytic properties fall between those of PTMEG and other polyesters.
O

H2C NH
H H2
catalyst H N C C OH
H2C
CH2 + H2O 5
n
C CH2 O
H2

Synthesis of polycaprolactam.

When reacting either ethylene carbonate or propylene carbonate with an aliphatic

diamine, a polyurethane can be produced (Figure 2.7). Poly (ethylene ether carbonate)
diols produce elastomers that have polyester polyol features when fabricated into
polyurethanes using methylene diphenyl diisocyanate and 1,4-butanediol. This was
13
shown using C NMR. The structure gives rise to potential for a very high virtual

8
cross-linking density.These carbonate-derived polyesters have superior hydrolysis
resistance compared to the traditional materials.
O O
O
CH2
C O + H2N CH2 NH2 HO CH2CH2O C NH CH2 NH C OCH2CH2 OH
H2C n n
O

Synthesis of polycarbonate polyol (Buist, 1968; Saunders, 1962).

Polymer containing polyester polyol; Polymer containing polyols consist of

dispersions of a solid polymer in the polyols are frequently used in the manufacturing
processes for flexible polyurethane foams. The use of such products provides
advantages such as an increase in the degree of opening the foam cells and
improvement of the mechanical properties, which are derived from an increased
hardness, compression strength, tear strength and tensile strength.

This allows a reduction in the polyurethane system density because it is possible to

maintain the same properties as obtained with higher densities and conventional
polyols, with the financial savings that the process involves.

The most frequent process are the polymerization, by using conventional polyol as
medium although there are also references to use of other types of polymers, such as
polyureas produced from polyisocyanates and polyamines, always in a polyol.

The reaction is carried out by the in situ polymerization of vinyl monomers, usually
either acrylonitrile or mixtures of acrylonitrile and styrene, in a carrier polyol in the
presence of free radical catalyst, such as azobisisobutyronitrile or benzyl peroxide at
temperatures around 80 to 90 oC. The choice of carrier polyol is determined by the end
application. Apart from free polyol and and dispersed polymer, the polymer polyol
contains a third and very important species which is called graft co-polymer. It is made
separately, for example by reacting a vinyl monomer onto the polyether backbone.

The reaction conditions should be controlled to obtain stable dispersions with the
required particle size distribution, in the range of 0,1 to 5 micron. The introduction of
styrene resolved the problems of polyol and foam discoloration. However, it is difficult
to make stable polymer polyols as the level of styrene is increased. 80 percent styrene
(based on the total vinyl monomers) is the maximum amount found in commercial
products. The references are less frequent to the use of hydroxylated polyesters, as is

9
the case of this work, and among the few known, practically none emphasizes their
use in specific applications (Capellades and Maria, 1987).

2.1.2.3 Acrylic polyol

Traditionally, acrylic resins are used in paints and coatings. Acrylic polyols are
employed in polyurethane coatings for automotive finish with good chemical
resistance and durability. Below these comonomers can be used in acrylic polyol
synthesis (Figure 2.8);

CH3
CH2 CH COOCH3
H2C C COOCH3
Methylcrylate
Methylmetacrylate
CH3
H2C C COO(CH2)3CH3
H
H2C C COO(CH2)3CH3

Butylacrylate
Butylmethacrylate
CH3
H2C C COOCH2CHCH2CH3
H2C C COOCH2CHCH2CH3 H
CH2CH3
CH2CH3
2-Ethylhexylacrylate
2-Ethylhexylmethacrylate
CH3
H2C C COOCH2CH2OH
H
H2C C COOCH2CH2OH
Hydroxyethylacrylate
Hydroxyethylmethacrylate
CH3
H2C C COOH
H
H2C C COOH
Acrylic acid
Methacrylic acid

H2C C
H

Styrene
Common monomers for acrylic polyol.

10
Acrylic polyol based PU coatings depend profoundly on the chemical nature of the
monomers used. Example of preparation of acrylic polyol reaction can be seen in
Figure 2.9;
O

OH
+ O
n
O COOH COOCH2CH2OH
OH

An example for preperation of acrylic polyol.

Thus, methylmethacrylate (MMA) confers exterior durability, excellent light stability,

hardness and water resistance. Styrene confers hardness, water stability but,
unfortunately, poor light stability. Butyl and 2-ethylhexyl acrylates and methacrylates
confer flexibility and acrylic and methacrylic acids confer adhesion to metals and
solvent/grease resistance (Lyons, 1970; Ferrigno, 1967).

2.1.2.4 Polysiloxane polyol

Polysiloxane chains display a combination of very interesting properties. These

include very low glass transition temperature (Tg) of (Tg = –123 °C), high thermal, UV
and oxidative stability, low surface energy, hydrophobicity, high gas permeability,
good electrical properties and physiological inertness or biocompatibility (Bruins,
1969).

As a result, it is very meaningful to use these kinds of polymeric chains to build an

oligo-polyol structure with terminal hydroxyl groups. The resulting structure called a
polysiloxane polyol gives polyurethane (PU) elastomers which conserve their high
elasticity at very low temperatures, after reaction with diisocyanates.

The synthesis of some experimental siloxane polyols is based on several reactions

developed in two steps:

Step I: Synthesis of a polysiloxane chain of molecular weight (Mw) of 1000-3000

daltons, having terminal -Si-H bonds, by using classic reactions. These kinds of
polysiloxanes with terminal -Si-H bonds are available commercially.

Figure 2.10 shows that a method of polysiloxane synthesis by using

dimethylchlorosilane and dimethyldichlorosilane in presence of water. The formation
of the product can be seen in the step 2.

11
 CH3 CH3 CH3 CH3 CH3

H Si Cl + Cl Si Cl + H2O H Si O Si O Si H + HCl

CH3 CH3 CH3 CH3 CH3

n

CH3 CH3 CH3 CH3 CH3 CH3

H Si O Si H + O Si O H Si O Si O Si H

CH3 CH3 CH3 n CH3 CH3 CH3

n

Polysiloxane synthesis methods.

Step II: The addition of the -SiH group to a compound having a double bond and a
hydroxyl group (allyl alcohol or allyl alcohol based polyethers). The reaction is
catalysed by platinum, palladium or rhodium catalysts as can be seen in Figure 2.11
(for example H2PtCl6, platinum complexes or even solid platinum supported catalysts).
Hydrolysis resistant -Si-C- bonds are formed” (Lyons, 1970; Ferrigno, 1967).

CH3 CH3 CH3

Pt catalyst
H Si O Si O Si H + 2 CH2 CH CH2 OH

CH3 CH3 CH3

n
CH3 CH3 CH3

HO H2CH2CH2C Si O Si O Si CH2CH2CH2 OH

CH3 CH3 CH3

n

PDMS diol synthesis.

2.1.2.5 Polybutadiene polyol

Polybutadiene diol is especially preferred because of its excellent hydrolysis and

chemical stability, and insulating properties. It is obtained by free radical
polymerization of butadiene, initiated by hydrogen peroxide and an alcohol as diluents.
Figure 2.12 shows synthesis of hydroxyl terminated polybutadiene reaction.

Synthesis of hydroxyl terminated polybutadiene.

Due to its very low glass transition temperature the PUs formed have excellent
elastomeric properties at extremely low temperatures. They possess great capacity to

12
accept fillers as asphalt, aromatic and paraffinic oils, pentanes, plasticizers and carbon
black.

Hydroxyl terminated polybutadiene microstructure is 60% of 1,4-trans, 20% of 1,4-

cis and 20% of 1,2-vinyl insaturations that turn possible further vulcanization and
chemical modifications (Lyons, 1970; Ferrigno, 1967).

2.1.2.6 Chain extender

The two main groups used as chain extenders are diamines and hydroxyl compounds.
Triols are also used where some cross-linking is required. The choice of chain
extender depends on the properties required and the process conditions. However,
diols are the most commonly used hydroxyl compound. They provide good properties
and processing speed with MDI-based prepolymers and diamines with TDI-terminated
prepolymers.

The molecular shapes of the isocyanate and extender molecule often are considered to
play a part in the ease of formation of hydrogen bonding. The molecules must be able
to come closer to each other for hydrogen bonding to take place.

There must be no steric hindrance to the two chains. Molecules with an even number
of carbons allow the hydrogen donor group (NH) to fit more easily to each electron
donor group (C=O). If the carbon number is odd, the fit is poor, and many groups
cannot participate in hydrogen bonding.

Experimentally it has been shown that the melting points of polyurethanes made with
a series of aliphatic diisocyanates with different number of carbons in the chain varied
with the number of carbons in the diisocyanate. Polyurethane fabricated with an odd
number of carbons in the isocyanate had a lower melting point than those on either
side with an even number of carbonatoms in the isocyanate chain (Clemitson, 2008).

Hydroxylated chain extender and crosslinkers are listed in Table 2.2 which interiors
chain extenders and crosslinkers’ chemical structure, OH funtction number and
molecular weight

13
 Hydroxylated chain extender and crosslinkers.
COMPOUND STRUCTURE F MW
Ethylene glycol HOCH2-CH2OH 2 62
Di-ethylene HOCH2-CH2-O-CH2CHOH
2 106
glycol
Propylene glycol HOCH2 CH OH
2 76
CH3
Di-propylene HOCH2 CH O CH2 CH OH
2 134
glycol CH3 CH3

1,4 Butane-diol HOCH2-CH2-CH2-CH2OH 2 90

2-Methyl-1,3- HOCH2-CH(CH3)-CH2OH
2 90
Propylene- diol
Water HOH 2 16
OH
N-N’-Bis-(2
CH2CHCH3
hydroxy-
N 2 221
propylaniline)
CH2CHCH3
(DHPA)
OH

1,4-Di-(2-
OH H2CH2C O O CH2CH2 OH
hydroxyethyl)
2 198
hydroquinone
(HQEE)
Diethanol amine HOCH2CH2NHCH2CH2OH 3 105
Triethanol amine N-(CH2CH2OH)3 3 149
CH2OH
Trimethylol
propane CH3 CH2 C CH2OH 3 134
CH2OH
Glycerine HOCH-CH2OH-CH2OH 3 92

Low molecular weight diamines (Table 2.3) are used as chain extenders in polyurea
and polyurethane/urea processes. Compared to their reaction kinetics with polyols,
they react much faster with isocyanates.

Due to their longer pot life, the less reactive aromatic diamines are used in cast PU
elastomers prepared in two-step processes. Aliphatic and aromatic amines are used as
chain extenders in polyurea, RIM processes and spray coatings, where their higher
reactivity results in shorter demold times.
14
The use of more reactive aliphatic or less reactive secondary aromatic diamines makes
possible to vary the system reactivity.

Diamines used as chain extender.

COMPOUND STRUCTURE MW
Hydrazine H2N-NH2 32
Ethylene daimine H2N-CH2-CH2-NH2 60

1,4-Cyclohexanediamine H2N NH2 114

H2N

CH2NH2

Isophorone diamine (IPDA) CH3

170
CH3

CH3

4,4’-Bis-(sec-butyl amine)
dicyclohexylamine. H3CH2CHC HN CH2 NH CHCH2CH3 322
(SBADCHM) CH3 CH3

4,4’-Bis-(Sec-butil amine)
diphenylmethane H3CH2CHC HN CH2 NH CHCH2CH3 310
(SBADFM) CH3 CH3

C2H5

Diethyl-toluene diamine
(DETDA) isomers 2,4 (80) (NH2) CH3 178
e 2,6 (20)
C2H5 NH2

4,4'-Methylene-bis(2- NH2 CH2 NH2

267
Chloroaniline) (MOCA)
Cl Cl

H2N
4-Chloro-3,5-diamino- O

Cl C O iBut
benzoic acid isobutylester 242,5
(CDABE) H2N

H3CS
3,5-Dimethylthio-
toluenediamine (DMTDA) - (NH2) CH3 214
isomers 2,4 (80) e 2,6 (20) H3CS NH2

O O
Trimethyleneglycol-di-p-
NH2 C O (CH2)2 O C NH2 314
aminobenzoate (TMGDAB)
4,4’-Methylene-bis-(3-
Cl Cl
chloro-2,6-diethylaniline)
(M-CDEA) 365
NH2 NH2

15
2.1.2.7 Reactions of isocyanates

Isocyanates are highly reactive chemicals and create several chemically different
products when combined with –OH and –NH functional sub¬stances.

Desired products and side products are formed in different amounts. The basic
reactions of isocyanate with different reagents are shown in Figure 2.13.

The high reactivity of isocyanate groups, especially in aromatic systems, toward

nucleophilic reagents is mainly due to the positive character of the C atom in the
cumulative double bond sequence consisting of nitrogen, carbon and oxygen. In the
isocyanate group, the electronegativity of the oxygen and nitrogen conveys a large
electrophilic character to the carbon in the isocyanate group.

The common reactions of isocyanates can be divided into two main classes: (1) the
reaction of isocyanates with compounds containing reactive hydrogen to give addition
products, and (2) the polymerization of isocyanates, i.e., self-addition reaction.
Isocyanates react with hydroxyl compounds to give urethanes.

Self Reaction (Cyclic dimerization and trimerization)

O
C

2 R N C O R N N R
C
O
R
N
3 R N C O O C C O This reaction
occurs at elevated
R N N R temperature.
C
O

Self Reaction (Carbodiimid formation)

Reaction with alcohols

R N C O + RıOH R NH C ORı
O
Urethane

Reactions of isocyanates with different reactants.

16
 R N C O + H2O R NH COOH RNH2 + CO2
carbamic acid

R N C O + R NH2 R NH C NH R
O
substituted urea

Reaction with amine

Reaction with carboxylic acid

R N C O + RıCOOH R NH C O C Rı
O O

R NH C R + CO2
O

Reaction with urethane (allophanate formation- This reaction occurs at elevated

temperature.)

O
R NH C ORı + R N C O R N C ORı
O C O
urethane NH
R allophanate

Reaction with substituted urea (Biuret formation)

O
R NH C NH R + Rı N C O R N C NH R
O C O
substituted urea NH
Rı

Figure 2.13 (continued) : Reactions of isocyanates with different reactants.

2.1.2.8 Catalyst

In terms of industrial productivity, the isocyanate group reacts rather slowly with
alcohols, water and itself in the absence of catalysts. The catalyst choice for PU's
17
manufacture is usually directed for obtaining an appropriate profile among the several
reactions that can occur during PU production processes.

Tertiary amines, organometallics (primarily tin containing compunds) and carboxylic

acid salts are used as catalyst in the reaction of isocyanates with water (blowing) and
polyols (polymer gelation). The catalyst functions as a controlling agent for the relative
reaction rates of the isocyanate with polyol and water.

Amine catalysts are generally considered as blowing catalysts since they tend to
catalyse the isocyanate water reaction better than the isocyanate-polyol reaction.
However, amines actually catalyse both reactions, with the relative rates of each
reaction being dependant on the specific amine catalyst used.

Organametallic catalysts are mainly seen as gelation catalysts although they take
partial role in the isocyanate–water blowing reaction. Organotins are the most widely
used, but organomercury and organolead catalysts are also used. The mercury catalysts
are very good for elastomers because they give a long working time with a rapid cure
and very good selectivity towards the gelation. The lead catalysts are often used in
rigid spray foams. “Potassium and carboxylic acid salts and quaternary ammonium
carboxylic acid salts are used to catalyse the trimerisation reaction and thus are used
mainly in isocyanurate foams” (Randall and Lee, 2002). For the tin salts the following
mechanism has been proposed Figure 2.14. The isocyanate, polyol and tin catalyst
form a ternary complex, which then gives the urethane products. Two routes have been
proposed for the complex formation. In the first route, the tin first adds to the polyol
then the isocyanate. In the second one, the tin adds to the oxygen of the isocyanate
then reacts with the polyol.
Ar
H Ar
N
N
ROH + ArNCO + SnX2 H C
C
O O O
R O
R Sn SnX2
X2

O Ar
H

Ar C R N

N O + SnX2
C
H
O
R O
SnX2

Mechanism for tin (II) salts.

18
The growing catalyst basicity promotes improved crosslink formation (alophanate and
biuret). Generally, with tertiary amines the higher basicity increases the catalytic
effect, except in the occurrence of steric hindrance. Triethylene diamine (TEDA) or
1,4-diazo (2,2,2)-bicyclo-octane (DABCO) have a stronger catalytic effect due to the
absence of steric hindrance. It is important to state that the catalyst specificity can vary
according to the system used. Therefore, attention should be paid for extraction of
correlations from studies done in different systems. Basically the catalyst should be
sufficiently nucleophilic to stabilize the isocyanate group by resonance, or to activate
the active hydrogen atom-containing compound. According to the basic catalysis
mechanism given in Figure 2.15, initially formation of a complex between the base
and the isocyanate group takes place which activates the NCO group and makes easier
the reaction with the non-paired electrons of the alcohol oxygen atom. Afterwards the
complex is decomposed, forming PU and regenerating the base.

K2 R'N C O
R N C O R N C O + B: R'OH
K1 BH
K3

H R
O O

R' N C O HNR C OR' + :B

B

Basic catalysis mechanism.

Ketonic Resins

Ketonic resins are generally used as additives in many applications including surface
coating industry. Their preparations goes back to 1890s (Hurst et al., 1951; Novotny,
1940; Hauben, 1890). They are prepared by the reaction of ketones with aldehyde
especially formaldehyde in the presence of basic catalyst. The first step of the
condenzation is a cross-aldol addition reaction to form methylol ketones. Further
reaction at higher temperatures gives the ketonic resin. First step of methyl ethyl
ketone-Formaldehyde resin formation is an acidic α-hydrogen on methylene carbon

19
rather than methyl carbon is removed by the base and the formed carbanion attacks the
carbonyl group of formaldehyde to form methylol ketone (Figure 2.16). Sometimes
dimethylol ketone might also be formed depending on the ratio of formaldehyde to
ketone. Through the condensation of methylols, the resin is formed by the effect of
base and temperature.

O O CH2O O
NaOH

H3C CH2 -H2O H3C CH OH

H3C CH

CH3 CH3 CH3

NaOH - H2O

H3C
O

HO OH

CH3 n

Methyl ethyl ketone-formaldehyde resin formation.

Formation of acetophenone formaldehyde resin is similar as seen below (Figure 2.17).

First step is removal of acidic α-hydrogen on methyl carbon by the base and the formed
carbanion attacks the carbonyl group of formaldehyde to form methylol ketone

O O CH2O O
KOH
-H2O OH
CH3 CH2 C
H2

KOH -H2O

O
H2 H2
HO C C C OH
H
n

Formation of acetophenone-formaldehyde resin.

20
Cyclohexanone-formaldehyde resin can also be prepared from cyclohexanone and
formaldehyde and its structure as follows. Sometimes dimethylol ketone is also formed
depending on the ratio of formaldehyde to ketone (Figure 2.18).

NaOH H2 H2
+ CH2O HO C C OH

n
O
O

Cyclohexanone formaldehyde resin.

Better preparation methods of ketonic resin have been recently achieved by using
solvent and phase transfer catalysts such as benzyl trimethyl ammonium chloride.
Resin formation time is reduced considerably (Doerfell et al., 1988 and Gloeckner et
al., 2009).

2.2.1 Modification of ketonic resin

By modifying ketonic resins, their desired physical properties such as melting point
and solubilities in solvents can be improved, and the number of application of the
ketonic resin can be increased. The modification is classified as modification of
ketonic resin during the preparation and modification of ketonic resin after the
preparation.

2.2.1.1 Modification of ketonic resin during the preparation (in situ

modifications)

Modification of ketonic resin can be achieved in situ by adding reactive compounds to

the polymerization flask during resin preparation (Kızılcan, 1999; Kızılcan, 2005). The
modifier may be added to the polymerization system either at the beginning or later
stage of polymerization depending on its reactivity. Phenolic compounds such as
phenol, cresols, bisphenol-A, acetaldehyde, glyoxal, amines such as melamine,
silicone tegomer with amine chain ends were used as in situ modifier compounds.
Recently, in situ alendronic acid modified ketonic resin was prepared (Figure 2.20).
Nano clay composites of modified ketonic resin and used for polyurethane preparation
(Önen, 2015). Structure and formation of alendronic acid modified ketonic resins
could be represented as Figure 2.19.

21
 O O
O
O CH2OH CH2OH
-
OH
+ H C H + CH2OH
80OC

CH2OH
O N
OH HOH2C
P O CH2
ONa
CH2 CH2 OH
H2N CH2 C + H C H H2C
OH 80°C
CH2
P
OH ONa HO C PO2HNa
O
PO2H2

80°C OH

CH2OH
HOH2C CH2 H2C CH2 OH

O N O
m n
CH2

H2C
CH2

OH C PO2HNa

PO2H

Formation of alendronic acid modified ketonic resin.

Other examples of in situ modified ketonic resin with bisphenol-C and rezorsine are
shown in the Figüre 2.20 below.
OH

HOCH2 CH2

O
HOCH2 CH2 CH2

OH n
HO OH

HO
CH2

In situ bisphenol and rezorsine modified CF-Resin.

22
Modified ketonic resins show changes in their melting temperature, solubility and
molecular weight.

2.2.1.2 Modification of ketonic resin after preparation via their functional

groups

Ketonic resins are also modified by the reaction of their functional groups with
appropriate reagents (Akar et.al., 1988 and Kızılcan et.al., 1993). Properties such as
solubility, melting point of modified resin are affected by the degree of modification.
Modifier compound such as acid chloride, acid anhydride, reacts with hydroxyl groups
of the resin. Hydroxyl amine, hydrazines, bisulfite may condense with carbonyl
groups. Besides, ketonic resin and modified ketonic resin have been used for
production of copolymer (Kızılcan et.al. 2012; Akar et.al., 1989) and as polyol in
polyurethane preparation (Baslas 1981; Eugene, 2004).

In the following Figure 2.21 after modification of acetophenone-formaldehyde resin

via its hydroxyl and carbonyl functional groups is shown.

C O
A O CH2 CH CH2 O A
C O
n
H O CH2 CH CH2 OH
n
H O CH2 CH CH2 OH
n
C G

HOOC
O O O
A: C CH3 , C , C

G: N OH , N NH C NH2 , N NH

After modification of acetophenone-formaldehyde resin via its

hydroxyl and carbonyl functional groups (Kızılcan, 1993).

2.2.1.3 Kabachnik-Fields reaction

Kabachnik-Fields reaction is a three component reaction. Carbonyl component, amine

component and dialkyl phosphite or trialkyl phosphite. General scheme is shown in
the Figure 2.22 below (Zefirov, 2008 and Keglevich, 2012).

23
 R1 OR4 R1 OR4

R3 NH2 + O + H P O R3 HN P O
R2
OR5 R2 OR5

Three component reaction.

There are a number of proposed mechanisms (Matveeva et.al., 2008). Several ketones
such as aliphatic ketones, aromatic ketones and cyclic ketones are used for this
reaction.

Phosphite may be alkyl and aryl phophites. Different aliphatic and aromatic amines
can also be used for this reaction. Water formed during the reaction and it is removed
azeotropically or by a proper water absorber such as Na2SO4. The conversion is
generally 80-95%. However, sometimes higher temperature and longer reaction time
might be necessary. It is reported that some catalysts increase the yield of conversion
as shown in the Figure 2.23 (Zefirov, 2008).
A B
R1 R1 OH R1 + R3 NH2 R1 NHR3
+ R3 NH2
O NR3
R2 1
-H O2
R2
R2 NHR3 R2 NHR3
3
2 6
OR4
OR4 OR4
D H P O
F G OR4
H P O H P O C
OR5 H P O
OR5 OR5
OR5

OR4 R2 OR4 R2
E + R3 NH2
HO HN
O P O P R3

OR5 R1 -H O 2 OR5 R1

5 4

Kabachnik-Fields reaction mechanism (Matveeva et.al., 2008).

Cyclohexanone and acetone react with an ethanol amine and diethyl phosphite
reagents (Kabachnik-Fields reaction) to produce diethyl 1-(2-hydroxyethyl) amino
cyclohexyl phosphonate and 1-(2-hydroxyethyl) amino acetone phosphonate
respectively (Figure 2.24) (Hindersin, 1968 and Smith 1974) and they are now
commercially available. Acetophenone gives the same Mannich reaction with
ethanolamine and diethyl phosphite at higher temperature and in longer reaction time
to get similar high yield.

24
 O
O OC2H5
P
OC2H5 OC2H5
+ HOCH2CH2NH2 + H P
OC2H5 NH
C2H4
OH
O

The structure of the product produced from cyclohexanone, ethanol

amine and diethyl phosphite.

Flame Retardants

A Flame Retardant (FR) is a molecule/polymer (inorganic or organic) useful for

inhibiting flame growth by one of the three mechanisms. FR is used to put out a fire in
three main ways: (i) passively (guard against fire), (ii) actively (extinguishing agent)
and (iii) some FR additives have multiple chemical applications (Ionescu, 2005;
Wilkie, 2009)

2.3.1 General approaches of flame retardant for polymers

Fire retardants can be broadly classified into 3 different additives: (i) gas phase, (ii)
endothermic, (iii) char forming / condensed phase.

They can also be classified in 7 different fire retardants in terms of their structures: (1)
Halogenated (gas phase): Decabromo diphenyl ether, hexabromo cyclododecanone.
(2) Phosphorus (gas and condensed phase): Encapsulated red phosphorous,
ammonium polyphosphate, aluminum phosphinate, tri phenyl phosphate, tricrecyl
phosphate, DOPO, phosphate polyols. (3) Mineral fillers (Endothermic): Al(OH)3,
Mg(OH)2 and Carbonates CaCO3, huntite, boehemite (AlOOH), talc, kaolinite. (4)
Intumescent (char forming / condensed phase):
Polyol + ammonium polyphosphate + melamine (melamine borate, melamine
phosphate). (5)

Inorganic (mostly condensed phase): Zinc borate (2ZnO•3B2O3•3.5H2O). (6) Nitrogen

based (gas and condensed phase): Melamine, melamine phosphate, melamine
cyanurate, HALS. (7)

Polymer nanocomposites (condensed phase): Organically treated layered silicates

(clays), carbon nanotubes/nanofibers, or other submicron particles at low loadings
(<10%).

25
2.3.1.1 Gas phase flame retardants (Examples: Halogen, Phosphorus)

They reduce heat in gas phase from combustion by scavenging reactive free radicals,
resulting in incomplete combustion. Halogen (F, Cl, Br, I) or Phosphorus (P-O or P)
are the most commonly used vapor phase radical scavenger/inhibitors. They can be
very effective at low loadings. However, they cause increase in carbon monixide and
smoke.

Gas phase flame retardants interact chemically with the free-radical process in polymer
combustion. The effectiveness of a gas phase flame retardant is determined by its
effective “Release Temperature” and the polymer degradation pathway of the material
being flame retarded.

2.3.1.2 Endothermic flame retardants (Examples: Metal Hydroxides,

Carbonates)

The decomposition of these flame retardants is endotermic. Its function is in the gas
phase and condensed phase by releasing non-flammable gases (H2O, CO2) which
dilutes the fuel and cools the polymer. They are generally very cheap in cost. However,
high loading is necessary and this degrades mechanical properties of polymer.

Endothermic decomposition cools the condensed phase, slowing down degradation, or

taking away heat that would lead to fuel release. The well known fire retardands are
Al(OH)3, Mg(OH)2 and some mineral carbonates such as hydromagnesite.

The effectiveness of a endothermic flame retardant is also determined by its effective

“release temperature” and the polymer degradation pathway of the material being
flame retarded.

2.3.1.3 Char forming flame retardants (Examples: Intumescents,

Nanocomposites)

They operates in condensed phase by preventing fuel release and providing thermal
insulation for underlying polymer. They provide a very robust method at providing
fire safety. However, they are not universally acceptable for all polymer systems and
it can be expensive.

With the use of high char-forming, crosslinking, and pre-ceramic materials, one can
potentially: (i) prevent fuel molecules from reaching the flame front and (ii) prevent

26
further depolymerization of the plastic. However, the char formation must activate
before peak decomposition temperature so it has time to set up and provide protection
(Figure 2.25).

Char forming flame retardants.

2.3.2 Phosphorus flame retardants

Phosphorus is a functional element for flame retardants since the element exists in
several oxidation states. It can be inorganic such as ammonium polyphosphate, red
phosphorus or organic such as phosphates, phosphonates, phosphinates.

Its main flame retardant action is formation of char layer on substrate surface and some
of them sometimes may operate simultaneously in both phases.

Phosphorus FR additives cover a wide range of chemical structures and can be both
gas and condensed phase FR additives. They can be very effective at lowering heat
release rate at low loadings of additive.

Phosphorus FR additives do not typically need synergists, but they are sometimes
more effective when combined with other types of flame retardants or elements, such
as halogenated FR (Phosphorus-halogen vapor phase synergy) and nitrogen
compounds (Phosphorus-nitrogen condensed phase synergy).

2.3.2.1 Mechanism of the effect of phosphorus-based fire retardants

Gas phase effect:

To act in the gas phase through the formation of PO• , PO2•, HOPO•, and HOPO2•
radicals which terminate the highly active flame-propagation radicals (HO• and H•).
These radicals are formed after the decomposition of the parent compound in the
flame. Therefore, flame inhibition does not depend on the form of the parent
compound. Gas phase effect on free radicals can be seen in Figure 2.26 in example of
phosphorus compounds.

27
 P PO• + P• + P2

PO• + H• HPO

HO • + PO• HPO + •O•

P2 + PO• PO• + P• and so on

Gas phase effect via free radicals.

Condensation phase effect:

In the condensed phase mechanism, the phosphorus flame retardant is thermally broke
down to give phosphoric acid which is further dehydrated to polyphosphoric acid in
the Figure 2.27.

P2O5 + 3H2O 2H3PO4

n H3PO4 polyphosphoric acid + (n-1) H2O

Condensed phase mechanism.

Polyphosphoric acid esterifies and dehydrates the polymer giving rise to unsaturated
carbonous species that make up a residue that protects the polymer surface from further
degradation.

Nitrogen based flame retardants are typically melamine and melamine derivatives (e.
g., melamine cyanurate, melamine polyphosphate, melem, melon). They are often used
in combination with phosphorus based flame retardants (Figure 2.28).

Char forming flame retardant.

2.3.3 Fire resistance polyurethanes

Polyurethanes are high combustible material and burn completely in case of fire. High
number of research have been carried out to increase the fire resistance of
polyurethanes. Fire retardants used in polyurethane formulation are halogenated fire
retardants, Organic phosphorus compounds and inorganic fire retardands.

28
2.3.3.1 Halogenated fire retardants

In the flame, halogenated organic fire retardants act by blocking the chain reactions
characteristic for the flame (W. Lyons, 1970). So any organic compound containing
chlorine or bromine decomposes by the effect of flame into the corresponding acids
(HCl or HBr) and these acids react with the most reactive radical existing in the flame,
the hydroxyl radical, HO* (Figure 2.29).

HO*+ HCl H2O + Cl*

Hydroxyl radical reaction mechanism.

The chlorine radical reacts with the organic substrate in Figure 2.30.

Cl*+ RH HCl + R*

Chlorine radical reaction mechanism.

Thus the chain reactions in the flame are terminated. This phenomenon is called self-
extinguishing.

2.3.3.2 Organic phosphorus compounds

Organic phosphorus compounds, irrespective of their structure, decompose to

polyphosphoric and methaphosphoric acids, which retain the acidity at higher
temperatures and catalyse the rapid decomposition of the polyurethane to carbon.
During fire extinguishing process, carbonaceous layer containing phosphorus is
formed, which is very difficult to burn. It provides a true protective layer for the rest
of polyurethane material and the process of burning is stopped (Hilado, 1969).

2.3.3.3 Organic phosphorus and halogen compounds as fire retardants

Generally, halogens act in the flame and phosphorus compounds in the polymeric
substrate. Having both groups of elements (halogens and phosphorus), in the same
structure leads to a synergism. The significance of synergism is that a phosphorus –
halogen combination has the same flame retardance effect at the lower concentration
of each element.

The presence of nitrogen in the structure of a flame retardant is very beneficial because
nitrogen is an element which is difficult to burn (Papa, 1970, Papa, 1972 and Ionescu,
et.al, 1998).

29
There are two types of organic flame retardants for polyurethanes: (i) Additive flame
retardants and (ii) reactive flame retardants (Backus, 1971).

2.3.3.4 Additive type flame retardants

The additive type of flame retardants are compounds containing chlorine, bromine or
phosphorus, boron and silicone without reactive groups to get involved in polyurethane
chemistry (without -OH, -NH2 or -NCO groups) as seen in the Figure 2.31. These
compounds are physically added to polyurethane and are not part of the polyurethane
structure.
O O
CH3
CH3
OCH2CHCl
OCH2CH2Cl ClCHCH2O P
ClCH2CH2O P OCH2CHCl
OCH2CH2Cl
CH3

Tris-(2-chloroethyl) phosphate (TCEP)

Tris-(2-chloroisopropyl) phosphate

(TCPP)

O
CH2Cl
CH2Cl
OCH2CHCl
ClCHCH2O P
OCH2CHCl

CH2Cl

Tris-(2,3 dichloropropyl) phosphate

Examples of well known additive flame retardants for polyurethane.

Dimethyl methyl phosphonate (DMPP) is another important flame retardant additive.

DMPP has a very high phosphorus content (P= 25%) (Papa, 1970):
O

OCH3
H3C P
OCH3

Dimethyl methyl phosphonate (DMPP).

30
Unfortunately, DMPP is not hydrolysis resistant and the acidity increases with
significant decrease in reactivity of the polyurethane formulation. Besides, the flame
retardant additives of his types of organic compounds such as tris (2-chloroethyl)
phosphate have a tendency to migrate, which later causes loss of flame retardancy.

For example, a rigid polyurethane foam containing tris (2-chloroethyl) phosphate

(TCPP) as a flame retardant, completely loses its flame retardancy after a year.

2.3.3.5 Reactive flame retardant

The chemically reactive flame retardants are generally polyols containing halogens,
phosphorus, boron, silicone and nitrogen (Backus, 1971).

These flame retardant polyols, have hydroxyl groups (generally terminal), react with
isocyanates in the process of polyurethane synthesis and they are chemically bound to
the polyurethane structure.

Chemically linked reactive flame retardants assure a permanent flame retarding effect
and stable physical properties in long term (Hilado, 1969).

Halogen containing polyols; Bromine containing polyols are very effective, reactive
flame retardants in polyurethane. One of the most representative bromine polyols used
in rigid and flexible flame retardant PU foams is 2,3 dibromobutene diol (Frisch, 1972)
is shown in the Figure 2.33.
Br

HOCH2 C C CH2OH

Br

2,3 dibromobutene diol.

Dibromo neopentylglycol is another low molecular weight reactive flame retardant,

(Termine and et.al., 1985 and Boulet, and et.al., 1974) with labile aliphatic -C-Br
bonds as shown in Figure 2.34.
Br CH2 CH2OH

Br CH2 CH2OH

Dibromo neopentylglycol.

31
The bromine linked to a double bond or linked to an aromatic nucleus are much more
stable structures. Bromine containing diol is based on tetrabromophthalic anhydride as
shown in Figure 2.35, and it is industrially produced (Papa, 1970; Jensen and et.al,
1982).
Br O
Br

O + HOCH2CH2OCH2CH2OH

Br
Br
Br O
Br COOCH2CH2OCH2CH2OH

Br COOH

Br

Formation bromine containing diol fromtetrabromophtalic anhydride.

A bromine aromatic polyol is obtained by the Mannich type reaction between 2,4
dibromophenol (or 2,6 dibromophenol) with diethanolamine and formaldehyde
(Paulik, 1998) or with oxazolidine (Modesti and et.al.,1994), followed by the
propoxylation of the resulting Mannich base with 2-3 mols of PO (Paulik, 1998;
Modesti and et.al.,1994) (Figure 2.36).
OH OH
CH2CH2OH CH2CH2OH
Br Br CH2N
N
+ H2C CH2 CH2CH2OH

O CH2

Br Br

OH
CH2CH2OH
CH3
Br CH2N H2C CH
+ 2
CH2CH2OH
O
CH3
CH3
CH2CHOH
Br
O CH2CH2OCH2CHOH
Br CH2N
CH2CH2OH

Br

Mannich type reaction between 2,4 dibromophenol (or 2,6

dibromophenol) with diethanolamine and formaldehyde.

32
The resulting bromine polyol has a bromine content of about 33-38% with hynumber
of 360-390 mg KOH/g and a viscosity in the range 16,000-25,000 mPa-25 °C.

Tetrabromobisphenol A is bromine containing raw material produced industrially. By

the ethoxylation of tetrabromobisphenol aromatic bromine diol is obtained with 8-9
moles of ethylene oxide (EO), (Figure 2.37).

Br Br
CH3

HO C OH + 2x
O
CH3
Br Br

Br Br
CH3

H OH2CH2C O C O CH2CH2O H
x x
CH3
Br Br

Ethoxylation of tetrabromobishenol A.

Recent trends of flame retardants in polyurethane;

In recent years, there has been an effort to eliminate halogens from all flame retardant
compounds, and utilize only halogen free flame retardants. Therefore, there is a
tendency to avoid and in turn finally ban the use of TCEP and TCPP, which are two
of the most widely used additive flame retardants for fabrication of fire resistant PUs.

This ban is due to the toxic and corrosive gases formed during combustion and
envorinmental concerns. Environmental and health concerns are now gaining
importance since toxic TCPP migrates and evaporates during the use of flame retardant
PU material and contaminate the atmosphere. The relative order concerning the
fireproofing efficiency of halogens is: Cl < Br < P. A flame retarded rigid PU foam
needs about 20-25 % chlorine or 5-6 % bromine or 1.5-2 % phosphorus (Lyons, 1970;
Hilado, 1969; Papa, 1970; and Backus, 1971).

Many reactive flame retardants for PU were developed, unfortunately only a few are
used effectively in practice. Phosphorus polyols are the most important reactive flame
retardants in PU. They can be examined in the following groups: Esters of ortho-
phosphoric acid, esters of phosphorus acid; phosphonate polyols, phosphine oxide
polyols,phosphoramidic polyols.

33
Esters of Ortho-Phosphoric Acid; These phosphorus polyols are produced by using the
following two methods; by the reaction of propylene oxide with polyphosphoric acids
(Papa, 1970 and Ferrigno, 1967) (Figure 2.38).

Propoxylation of polyphosphoric acid.

The resulting phosphorus polyol (18.8) has a hydroxyl number of 300-310 mg KOH/g,
a phosphorus content of 9.5-10% and a viscosity of 1,600-3,000 mPa-s at 5 °C.

They can also be produced by the condensates of phosphorus pentoxide with n-butanol
(Papa, 1972) and the resulting product reacted with propylene oxide (Figure 2.39).

The resulting phosphorus diol has a hydroxyl number of 210-215 mg KOH/g and a
phosphorus content of 11.2% (Papa, 1972).

P4O10 + 4 HOCH2CH2CH2CH3

O O CH3
H3CH2CH2CH2CO H2C CH
OH 2
+
P O P O
HO OCH2CH2CH2CH3

O O CH3

H3CH2CH2CH2CO OCH2CHOH
P O P
HOHCH2CO OCH2CH2CH2CH3

H3C

Propoxylation of phosphorus pentoxide with n-butanol condensate.

34
These phosphorus polyols with ortho-phosphoric ester structure are not preferred in
PU formulation because they are not resistant to hydrolysis (Figure 2.40).
CH3 CH3

3 HOCHCH2OCH2CHOH+ P O

H3C H3C

HOHCH2COH2CHCO CH3 CH3

P OCHCH2OCH2CHOH + HO

HOHCH2COH2CHCO

H3C H3C

Formation of tris (dipropylene glycol) phosphite.

Unfortunately, trialkyl phosphites are also extremely susceptible to hydrolysis and

they hydrolyze morerapidly than the ortho-phosphoric esters. Therefore, they are not
currently used in industry.

Phosphonate Polyols;

a) By Mannich reaction with dialkyl phosphite

The phosphonate polyols contain -P-C- bonds which are very resistant to hydrolysis.
The phosphonate (Figure 2.41) polyols are one of the most important groups of
reactive flame retardants. They are used in many formulations of polyurethane foams
(Beck and et.al. 1963, Ferrigno, 1967).

Phosphonate.

One of the phosphorus polyol of significant commercial importance is diethyl-N,N bis

(2-hydroxyethyl) aminomethyl phosphonate. It is obtained by a Mannich reaction
between diethylphosphite, formaldehyde and diethanolamine (Figure 2.42) (Papa,
1972; Beck and et.al., 1963; Raymond and Hindersin, 1968):

35
 Formation of Diethyl-N,N-bis(2-hydroxyethyl) aminomethyl
phosphonate.

The same product is easily obtained by reacting diethylphosphite with an oxazolidine

(Figure 2.43) (Ionescu, 1998; Ionescu, et.al. 2003).
O
H2C CH2 O
C2H5 O
C2H5 O H2 CH2CH2OH
P H + O
N P C N
C2H5 O HOH2CH2C
C C2H5 O
H2 CH2CH2OH

Diethyl-N,N-bis(2-hydroxyethyl) aminomethyl phosphonate from

oxazolidine.

This phosphonate polyol is very resistant to hydrolysis and has in its structure both
phosphorus and nitrogen.

b) Mannich reaction with bishydroxyalkyl phosphite: Phosphorus acid is

alkoxylated with propylene oxide to produce a bis (hydroxypropyl) phosphite which
is then reacted with oxazolidine. As final product, a tetrafunctional phosphonate polyol
is obtained (Ionescu, 1998) (Figure 2.44).
H3C
O CH3 O

HO H2C CH H OHCH2C O
P H + 2x x P H
O
HO H HOCH2C O
x
H3C

Formation of tetrafunctional phosphonate polyol.

36
This phosphonate polyol has a phosphorus content of 7-7.5 %. By reacting of
dimethylphosphite with acetone and monoethanolamine higher phosphorus content
(15%) phosphonate polyol is formed (Figure 2.45) (Kabachnik-Fields).
O O
CH3 O
OCH3 OCH3
HOCH2CH2NH2 + C + H P HOH2CH2CHNC P
H3C CH3 OCH3 OCH3
CH3

Reaction of dimethylphosphite with acetone and monoethanolamine.

Using reactive cyclic phosphites as raw materials gives a different polyol. (Figure
2.46) (Salkowski, 1974):
O
O
H2C CH2CH2OH
P CH2CH2OH + CH3CHO + HN
H2C CH2CH2OH
O

O
HOH2CH2CO
CH2CH2OH
H
P C N

HOH2CH2CO CH2CH2OH
CH3

Reaction of cyclic phosphite with formaldehyde and diethanolamine.

Phosphonate polyols may be obtained by the direct alkoxylation of phosphonic acids

with propylene oxide (Figure 2.47), at moderate temperatures (70-90 °C) (Papa, 1972;
Ionescu, et.al, 1998).
O O CH3
CH3
OH O CH2CHO H
HC CH
R P + 2x R P CH3 x
O O CH2CHO H
OH x

O O
HO CH3
OH
P R P H2C CH
+
HO 4x
OH O

H3C O O CH3
H OHCH2C O O CH2CHO H
H3C x
P R P x
CH3
H OHCH2C O O CH2CHO H
x x

Phosphonate polyols obtained by the direct propoxylation of

phosphonic acids.

37
A phosphonate polyol is obtained by the propoxylation of phenylphosphonic acid in
Figure 2.48 (M. Ionescu et.al, 1998):
O O CH3
CH3
OH O CH2CHO H
HC CH
P + 2x P CH3 x
O O CH2CHO H
OH x

A phosphonate polyol is obtained by the propoxylation of

phenylphosphonic acid.

Phosphonate polyols are very efficient flame retardants in practice. These phosphorus
polyols is stable over time of formulated polyols containing phosphonate and water as
reactive blowing agent, with no significant loss of reactivity.

Cyclic and aromatic compounds and polyısocyanurate;

Improving method of the flame retardancy of rigid PU is to introduce highly
thermostable structures such as aromatic structures, thermostable isocyanuric,
oxazolidone or imidic rings. This effect is due to the high char yield resulting from the
burning process of the aromatic structures with very low ratio of H:C and to the
presence of the rigid cyclic aromatic nuclei (Figure 2.49) (Ionescu, et.al, 1998).
OCN NCO

H2C CH2
O

>70 °C N N
OCN CH2 NCO

O N O

CH2

NCO

Isocyanurate Reaction.

A very high efficiency of flame retardancy is obtained by generation in the foaming

process of very thermostable isocyanuric rings, by the trimerisation of an excess of -
NCO groups. The resulting PU / polyisocyanuric foams (PIR) foams, having both
urethane groups and isocyanuric rings, in combination with phosphorus compounds,
and additive or reactive flame retardants, give a very high fireproofing efficiency.

38
 EXPERIMENTAL

Materials

The list of chemicals used in the experiment are listed with their companies. Dimethyl
sulfoxide (Merck), toluene (Merck), isopropyl alcohol (Merck), styrene (Merck),
trimethiol propane (Merck), benzyl peroxide (Merck), formaldehyde (Merck),
isocyanuric acid (Merck), methyl ethyl ketone (Merck), 2,4 dichloro acetophenone
(Merck), diethanol amine (Merck), acetone (Merck), deuterated chloroform (Merck),
hydrochloric acid (Merck).

Tris (1-Chloro-2 propyl) phosphate (TCPP-Lanxess), tetra-isopropyl titanate (Dorf

Ketal), polymeric methylene diphenyl diisocyanate (PMDI-Bayer), polyether polyol
(Voranol RN 411-Dow Company), n- pentane (Shell), silicone stabilizer (Tegostab B
8443-Evonik), catalyst (Dabco TMR-Air Products) 4,4'-methylene diphenyl
diisocyanate (Bayer) 1,4 butanediol (Lyondell), natural oil based polyol (Priplast 3192,
f:2, Croda), adipic acid (Invista), diethylene glycol (Sabic), acetone (J. T. Baker),
tetrahydrofurane (VWR Prolab), vinylphosphonic acid dimethyl ester (VPADME-
Basf), dimerdiol (Pripol 2033-Croda), sodium hydroxide (Carlo Erba Reagents),
potassium hydroxide (Carlo Erba Reagents), dichloromethane (J. T. Baker), cyanuric
acid.

Diethyl phosphite (Aldrich), diphenyl phosphite DPP (Aldrich), ethanol amine

(Aldrich), cyclohexanone (Aldrich), methanol (Aldrich), benzyl trimethyl ammonium
chloride (Aldrich), diethhyl phosphite DEP (Aldrich), diphenyl phosphate (Aldrich),
tris (hydroxyethyl) isocyanurate (THEIC-Aldrich), melamine (Aldrich), acetophenone
(Aldrich).

Analyzes are performed with the equipments that given on Table 3.1. Also that table
interiors company of equipments and their explanation.

Also Figure 3.1 shows pictures of LOI, horizontal test chamber and UL94 cabinet’s
pictures.

39
 Measurments

Table 3.1 : Equipments.

Method Company Explanation
FT-IR Thermo Used for the monitoring of the reaction
Spectroscopy Nicolette steps
5700 with
ATR
Stress Strain Test Zwick Used for measurement of % modulus and
Machine elongation at break.
Martindale Atlas Used for measuring abrasion resistance of
synthetic leather.
GPC Waters Used for the monitoring of the molecular
weight distribution.
Shoe Sole Lab Gusperti Used for defining cream time, demoulding
Trial Machine time, flowability of polyurethane in the
mould

Shoe Sole Flex Çiftçi Used for defining flexibility of certain shoe
Machine Makina sole.

Horizontal Flame Atlas Used for measurement of flame retardant

Chamber properties of synthetic leather
GC-MS Agilent 1-chloropropan-2-ol was recorded using
Agilent 5975C MSD with triple-axis
detector and Agilent 7890A GC system.

Thermogravimetric Seiko Exstar Measurements were performed, under a

Analysis TG/DTA nitrogen atmosphere with a heating rate of
7200
10 ˚C min-1, 30 ˚C to 500 ˚C and a sample
weight from 1 to 2 mg.

Limiting Oxygen Marestek The test was performed per ASTM D 2863.
Index (LOI) Company The specimens were
120/12/12mm3(Length/Width/Thickness),
five specimens per sample were measured,
and their average values are reported.

40
 Table 3.1. (continued) : Equipments.

UL-94V Marestek Test was performed according to the testing

Company procedure of ASTM D3801.

Standard Test Methods for Testing

Polyurethane Raw Materials:
Determination of Hydroxyl Numbers of
Metrohm
OH Value
Autotitrator Polyols ASTM D4274-05 was applied as
procedure.

Acid Value Metrohm Determination of Acid and Alkalinity

Autotitrator Numbers of Polyols ASTM D4662-03 was
applied as procedure
.

Viscosity Brookfield Determination of Viscosity of Polyols

RVDV-II+ ASTM D4878-03 was applied as procedure
Model
viscosimeter. and viscosity measurement.

H-NMR & P-NMR Agilent CDCl3 solution on a chemical shifts (d in

VNMRS ppm) were reported down field from
(Varian 500
MHz) tetramethylsilane.
spectrometer

Foam Qualification Foamat Simultaneous measurement of foam rise

System height, reaction temperature, rise pressure,
curing, weight loss and viscosity.
Determination pf cream time, gel time and
tack free time of foam.

41
 Figure 3.1 : Picture of LOI, horizontal test chamber, UL 94 cabinet and foamat.

3.2.1 Evaluation of flame retardancy

The following describes the different techniques used to assess the flame retardancy
of polyurethane systems including composite materials.

3.2.1.1 Thermal gravimetry analysis (TGA)

TGA determines the thermal stability of the cured formulation by monitoring the loss
of mass of a heated sample with increasing temperature. When discussing the flame
retardancy of a polymer, one commonly quotes the decomposition temperature (Td),
which represents the temperature at which 10 % of the initial weight is lost. The
charring ability of the formulation can also be extrapolated from the residual weight
once all solid is thermally stable (T> 600 °C).

3.2.1.2 UL 94 test

UL 94 test is a common test for flame retardancy. It measures the flammability of a

material by a defined ignition source. During the test, a small sample (13 mm width x
4 mm thick x 50 -125 mm high) is exposed for 10 s, either vertical or horizontally, to
a small calibrated Bunsen burner flame (25 mm of height). To test a specific
formulation, five samples are ignited twice and the time to extinguishment after each

42
ignition is recorded. The flammability is rated as a function of the time the specimen
keeps on burning after the removal of the flame and the total time to extinguishment.
A material is considered non-flammable once it is classified as V0 (ISO 1210).

3.2.1.3 Oxygen index test

LOI measures the minimum concentration of oxygen in the atmosphere required to

maintain a candle like burning of a material. Materials with a higher LOI value are less
flammable. Materials with LOI under 21 %, which is the concentration of oxygen in
air,are considered as flammable (ISO 4589-2). On the other hand, materials with LOI
over 26 % are considered self-extinguishing.

Synthesis Of Styrene Graft Polyester Polyol

3.3.1 Synthesis of saturated polyester polyol

Condensation of adipic acid with ethylene glycol and 1:2 molar ratio was carried out
at 225–230 °C. Volatiles were distilled-off under ambient pressure for 5 h. Then
additioned Tyzor TPT catalyst increased the rate of esterification and shortened the
distillation time to about 2 hour. At this point the acid number ranged between 15 and
20 mg KOH/g. Further lowering of the acid number was accomplished by distilling-
off water from the reaction mixture under reduced pressure (1 atm). This brought the
reaction to almost completion and the acid number to about 0,5 mg KOH/g. The
atmospheric Pressure distillate contained mostly water (70–90 %), and the distillate
obtained under reduced pressure contained mostly ethylene glycol (90%). Reaction
media is cooled rapidly (Figure 3.2).

Figure 3.2 : Polyester polyol.

3.3.2 Styrene grafting saturated polyester polyol

Four necked flask was charged with 50 g polyester polyol and temperature increased
50 oC. Styrene monomer (6, 9, 12, 15%) and BPO [(1,2,4) g / 1000g Styrene] added at
2 hour while nitrogen feeding and stirring. Temperature increased 120 oC and reaction
carried out 6 hour at this temperature. At the end of the reaction hold 1 hour under
vacuum and cool.
43
3.3.3 Synthesis of unsaturated polyester polyol

Maleic anhydride and eyhlene glycol and catalyst (Tyzor TPT; 0.0013 g /Total Mixture
g) kept in a pilot reactor (25 ml ) bottomed, mechanical stirrer, nitrogen inlet, fraction
column and set temperature at 100 oC. Adipic acid add in the reactor and adjust mixer
to 50 rpm. When raw material completely melt, reaction mixture was slowly heated up
to 150 oC with continuous nitrogen flow. Side product water formed result of reacting
acid and glycol, collected into collection container. When water in flow is very slowly,
vacuum was opened and temperature set 230 oC The reaction (Figure 3.3) was
monitored periodically by checking the acid value and was stopped when the acid
value reached 0.5 mg KOH via titration.

Figure 3.3 : Unsaturated polyester polyol.

3.3.4 Styrene grafting unsaturated poliester polyol

Four necked flask was charged with 50 g polyester polyol and temperature increased
50 oC. Styrene monomer (6, 9, 12, 15%) and BPO [(1,2,4) g / 1000g Styrene] added at
2 hour while nitrogen feeding and stirring. Temperature increased 120 oC and reaction
carried out 6 hour at this temperature. At the end of the reaction hold 1 hour under
vacuum and cool. Equation is shown in Figure 3.4.

Figure 3.4 : Styrene grafted unsaturated polyester polyol.

44
 Synthesis Of Ketonic Resins

3.4.1 Mek-formaldehyde resin

Four necked flask was charged with 72 g methy ethyl ketone and 162 ml formaline
(%37 formaldehyde solution) and heated to 70 oC while stirring. Then 6,7 ml %35
NaOH solution was added with dropping funnel (mechanical srirrer speed: 50 rpm)
When the temperature of the mixture rose to 80 oC, 3.3 ml %35 NaOH solution was
added. Stirring operation was going on 2.5 hours. When reaction (Figure 3.5) was
completed PH was arranged to 7 with diluted HCl and te upper phase was decanted.
The resin was washed several times with hot water and dried at 120 oC under vacuum.

Figure 3.5 : Mek-formaldehyde resin formation.

3.4.2 Cyanuric acid-formaldehyde reaction

Four necked flask was charged with 5.16 g cyanuric acid and 10 g formaline (%37
formaldehyde solution) and heated to 70 oC while stirring. Cyanuric acid was solved
in formaline and 30 min later colour of the solution became yellow and viscosity
increased dramatically. The resin was washed several times with hot water and dried
at 120 oC under vacuum (Figure 3.6).
O OH O
O
HN NH N OH
3 N
+ H H
O O O
N O N
H
HO

Figure 3.6 : Reaction of cyanuric acid and formaldehyde.

3.4.3 Acetophenone-formaldehyde resin

Method 1;

Four necked flask was charged with 67 g acetophenone and 30 g formaldehyde

(100mL of %37 formaldehyde solution) and heated to 90oC while stirring. Then 10 g

45
%40 NaOH solution was added with dropping funnel. After 8 hour, 6.5 g %40 NaOH
solution was added. 7 hour later, the upper phase was decanted. The resin was washed
several times with hot water and dried at 150oC under vacuum. Solubility of resin was
measured at DMF, toluene and acetone.

Method 2 ( after patent 4731434, Dörffel, 1988, and us 2009/0012245 A1, Glockner,
2009);

60 g acetophenone, 17 mL methanol, 18 mL formalin (30%) solution and 0.15 gbenzyl

trimethylammonium chloride are introduced into a reaction flask and mechanically
stirred while heating to 50oC. This is followed by dropwise addition of aqueous 50%
by weight KOH solution with further stirring in 20-30 minutes. In the meantime the
temperature is brought to 84oC. This is followed by dropwise addition of further 30
mL formalin (30%) solution over a course of 1.5 hours and the mixture is maintained
under reflux for a further 2 hours. After cooling, supernatant aqueous phase above the
resin separated. The residue crude resin is washed with hot water several times and
acidified with acetic acid and finally dried under vacuum at 130oC (Figure 3.7).

O O
KOH H2 H2
CH3 + CH2O HO C C C OH
H
n

Figure 3.7 : Reaction of acetophenone and formaldehyde.

3.4.4 Acetophenone-formaldehyde-dichloroacetophenone resin

Four necked flask was charged with 67 g acetophenone 30 g formaldehyde (100 mL

of % 37 formaldehyde solution) and 10 g 2,4-dichloracetophenone and heated to 90oC
while stirring. Then 10 g 40% NaOH solution was added with dropping funnel. After
8 hour, 6.5 g 40% NaOH solution was added. 7 hour later, the upper phase was
decanted.

The resin was washed several times with hot water and dried at 150 oC under vacuum.
Solubility of resin was measured at DMF, toluene and acetone. Reaction is shown in
Figure 3.8.

46
 Figure 3.8 : Reaction of acetophenone, formaldehyde and dichloroacetophenone.

3.4.5 Acetophenone-formaldehyde-dichloroacetophenone-cyanuric acid

Four necked flask was charged with 70 g Acetophenone-Formaldehyde-

Dichloroacetophenone resin (3.3.4.) and 4 g cyanuric acid and heated to 70 oC while
stirring. After 45 minutes 7 g formaldehyde added because of the solubility of cyanuric
acid. One hour later dried at 150 oC under vacuum.

3.4.6 MEK-formaldehyde-melamine reactions (a)

Four necked flask was charged with 7.2 g (0.1 mol )methy ethyl ketone and 41.1 g (0.5
mol) formaline (37% formaldehyde solution) and to increased pH to 11, 0.67 g
triethylamine added and heated to 80oC while stirring. At this temperature 6 hours
reaction carried out. At the end of the reaction transparent liquid resin obtained and
dried 120oC under vacuum. Four necked flask was charged with 9 g resin, 0.5 g
melamine, 0.5 ml water and to decreased pH to 3.5, 1 N HCl added while stirring.
Viscous liquid resin obtained. Reaction is shown in Figure 3.9.
O H2N N NH2

H3C NaOH
+ + CH2O
CH3 N N

NH2

H3C
O
H2 H H
HO m O C N N N CH2
CH3

N N

HN CH2O

Figure 3.9 : Reaction of methyl ethyl ketone, formaldehyde and melamine.

47
3.4.7 MEK- formaldehyde –melamine reactions (b)

Four necked flask was charged with 72 g methy ethyl ketone and 162 ml formaline
(37% formaldehyde solution) and heated to 70oC while stirring. Then 6.7 ml 35%
NaOH solution was added. When the temperature of the mixture rose to 80oC, 3.3 ml
35% NaOH solution , melamine (7.2 g) was added that 22 g formaline (37%
formaldehyde) were mixed and added continously at a gradually increasing rate
sufficient to maintain vigorous reflux. After 3 hours, the reaction was completed and
the upper phase was decanted. The resin was washed several times with hot water and
dried at 120oC under vacuum.

3.4.8 MEK-formaldehyde-cyanuric Acid

Four necked flask was charged with 72 g methy ethyl ketone and 162 ml formaline
(37% formaldehyde solution) and heated to 70oC while stirring. Then 6.7 ml 35%
NaOH solution was added. When the temperature of the mixture rose to 80oC, 3.3 ml
35% NaOH solution , cyanuric acid (7.2 g) was added that 22 g formaline (37%
formaldehyde) were mixed and added continously at a gradually increasing rate
sufficient to maintain vigorous reflux. After 3 hours, the reaction was completed and
the upper phase was decanted. The resin was washed several times with hot water and
dried at 120oC under vacuum.

3.4.9 Synthesis of cyclohexanone-formaldehyde resin (CF-R)

The resin product which generated by reaction between cyclohexanone and

formaldehyde is shown in the Figure 3.10.

H2 H2
HO C C OH

n
O

Figure 3.10 : Cyclohexanone formaldeyhde resin.

Into a three-necked flask, 98 g of cyclohexanone and 30 g of formalin 20 g

cyclohexane were added and heated to 60oC while stirring then added was 0.5 mL of
20% NaOH solution in equal portions. When the temperature of mixture rose to 75-
80oC, refluxing began and a mixture of 3.7 mL of 20% NaOH solution and 100 mL
formalin was added in equal potions in 30 minutes. Speed of Stirring was increased

48
while keeping pH about 10-11. Reaction is completed after 3 hours then water phase
was decanted. Residue was washed with hot water 5-6 times.

3.4.10 Cyanuric Acid - formaldehyde - diethanol amine

a) Synthesis of N-hydroxy-ethyl-1,3-oxazolidine:

Synthesis of N-hydroxy-ethyl-1,3-oxazolidine and of the Mannich base was performed

in a one litre four-neck round-bottom flask filter with stirrer, thermometer, dropping
funnel and condenser.N-hydroxy-ethyl-1,3-oxazolidine was obtained by the reaction
of 1 mol of diethanolamine (98%) with 1 mole of formaldehyde (as paraformaldehyde
97-98 %) at 55-65oC during 1-2 hours. The 1,3-oxazolidine was anhydrized by vacuum
distillation, during 2 hours at 15-20 mm Hg and temperature of 80-95oC (Figure 3.11).

Formaldehyde Diethanolamin

Figure 3.11 : Formation of 1,3 Oxazolidine from diethanol amine.

b) Mannich Base synthesis

351 g (3 moles) N-hydroxy-ethyl-1,3-oxazolidine with 1,5 % water content 129 g (1

mol) anhydrous cyanuric acid was added in portions at temperature between 45-50oC.
The reaction is slighty exotherm. After the entire amount of cyanuric acid was added,
temperature was increase to 110 – 120oC and maintained for 1 h under stirring. The
reaction is practically quantitative (99.2% yield) after 2 hours. Cyanuric acid –
isocyanuric acid keto – enol equation is shown in Figure 3.12.

Figure 3.12 : Keto – enol equation of cyanuric acid.

49
Figure 3.13 shows the reaction between cyanuric acid, formaldehyde and diethanol
amine.

Figure 3.13 : Mannich base produced from cyanuic acid - formaldehyde – diethanol
amine.

3.4.11 Modification of ketonic resins with ethanol amine/DEP and DPP

Modification of ketonic resin with ethanol amine and DEP is shown in Figure 3.14.

Figure 3.14 : Modification of MEK-F resin by reaction with ethanol amine and
DEP.

Reaction of ketonic resins with Diethyl phosphite (DEP) and diphenyl phosphite
(DPP) with the methods based on modified US Patent 3905922 (Smith et .al., 1975)
and US patent 3385914 (R.R. Hindersinn et.al.1968).

Method I:

Two steps process; Into a three-necked flask 10 g CF-Resin and 6.1 g (0.1 mole) of
ethanolamine were added in 100 ml toluene. The resulting mixture was heated under
reflux and the water was collected continuously by Dean-Stark trap for 2 hours. Then,
25 mL toluene solution of 0.1 mole diethyl phosphite was added over a period of 20
minutes. During the addition, the temperature was kept below 55oC by cooling. The

50
resulting mixture was stirred for further 2 hours. At the end of this period, toluene was
removed under reduced pressure at 50 oC and the formed product was dried in vacuum.
The modified resin was dissolved in a small amount of CH2Cl2 and poured into excess
hexane to precipitate the resin. Solvent was decanted and the resin was washed with
hexane twice and dried under vacuum.

Method II:

Using Na2SO4 as water absorber; 20 g acetophenone –formaldehyde resin was

dissolved in hot toluene and cooled to room temperature. 9.2 g ethanol amine and 35
g diphenyl phosphite was added and stirred and then 30 g dry Na2SO4 added. The
temperature of the mixture was increased to 80oC and kept for 4 hours. After cooling
to room temperature, the mixture was filtered and the filtrate evaporated with a rotary
evaporator to dryness at the temperature below 80oC.

Method III:

Modification of AF-R with ethanolamine and DEP using Mg(ClO4)2 catalyst; 20 g

acetophenone-formaldehyde resin 9.2 g ethanol amine and 26.1 diethyl phosphite were
dissolved in 50 ml dichloroethylene. 2 g of Mg(ClO4)2 was added as drying agent and
catalyst. The temperature of the mixture was increased to 80oC for 4 hours. After
cooling to room temperature, the mixture was filtered and the filtrate evaporated with
a rotary evaporator to dryness at the temperature below 80oC.

Synthesis THEIC-Tris (2-chloroethyl) Phosphite

Reaction of tris isocyanurate with tris phosphite and the final product is shown in the
Figure 3.15.
HO

OH
Cl

O N O
O
+ O O N O
Cl P Cl - ClC 2H5OH
N N
O
N N
O
HO OH
O
O
O OH
P
Cl O

Cl

Figure 3.15 : Reaction of tris (hydroxyethyl) isocyanurate (THEIC) with tris (1

Chloro-2 propyl) phosphite.

51
After putting THEIC (0.05 mol; 13.05 g) to 50 mililitre tri-neck round-bottom flask,
reaction temperature was increased to 100 ˚C. When melting of THEIC was complete,
mixture of tris (2-chloroethyl) phosphite (0.05 mol; 85%; 15.847 g) were dropped with
dropping funnel during 3 hours. The reaction was continued at 100˚C during 3 hours.
Distilled by vacuum distillation, during one hour at 47-51 mmHg . FR is a slightly
viscose liquid, with the following characteristics: viscosity at 25°C 2560 cP; OH
content 314 mg of KOH/g.

Synthesis THEIC-TCPP

Reaction of tris isocyanurate with tris phosphate and final product is shown in the
Figure 3.16.
Cl

O
O P O
Cl
OH O
O O
HO HO Cl
Cl
N N O Catalyst N N
+ P
O
+
O N O O O N O
O HO
Cl

OH O Cl
Cl O
P
O
O

Cl

Figure 3.16 : Reaction of tris (hydroxyethyl) isocyanurate (THEIC) with tris (1

Chloro-2 propyl) phosphate (TCPP).

After adding THEIC (0.65 mol; 130.5 g) to 500 mL three-necked round-bottom flask,
reaction temperature was increased to 165˚C. When melting of THEIC was complete,
mixture of TCPP (0.65 mol; 212.94 g) and dibutyltin diluarate (0,07 %) were dropped
with dropping funnel during 2 hours.

The reaction was continued at 180˚C during 5 hours. The 1-chloropropan-2-ol was
distilled by vacuum distillation, during 8 hours 65 mm Hg and temperature of 140˚C.
THEIC-TCPP product is a slightly viscose light yellow liquid. Picture of reaction
system is shown in the Figure 3.17.

52
Figure 3.17 : Picture of reaction system of tris (hydroxyethyl) isocyanurate (THEIC)
with tris (1-Chloro-2 propyl) phosphate (TCPP).

3.6.1 Preparation of the polyurethane rigid foam

PUR rigid foams were prepared by a one-shot and free-rise method. The chemical
compositions are shown in Table I. All of the raw materials (including FR) were mixed
well in a paper cup with the a high-speed mechanical stirrer (3000 rpm). After waiting
for removing the foam at the surface of mixture, PMDI which was calculated from
mixture OH equivalent weight was used excess (NCO/OH=1.3). Calculated PMDI
amount was poured to mixture, and then, were mixed with high speed mechanical
stirrer (3000 rpm). After mixing 10 s mixture was poured to mold. After preparation,
the foam samples were kept in an desiccator at room temperature for 24 h before
testing. Composition of rigid polyurethane foam is shown in Table 3.2.

Table 3.2 : Chemical composition of rigid polyurethane foam.

Material Phpa
Polyether polyol 100
Pentane 0.7
Tegostab B 8443 2.0
Distilled water 0.3
Flame retardant (FR) 5-10-15
Dabco TMR 1,5
PMDI 130

a Parts per hundred of polyol by weight.

53
 Vinyl Phosphonic Acid Dimethyl Ester Grafting Onto Unsaturated Polyester
Polyol

Polyol which obtained from AA + DEG , kept in a four necked round bottomed flask,
which is placed over an laboratory heater mantle and equipped with thermometer,
mechanical stirrer, nitrogen inlet, fraction column and set temperature at 150 oC.
Mixture that is vinylphosphonic acid dimethyl ester or vinylphosphonic acid
(VPADME or VPA) and benzoyl peroxide, dropped into the flask. The reaction
(Figure 3.18) was monitored periodically by checking the acid value and was stopped
when the acid value reached below one. Water that is occurring result of reaction, was
removed by vacuum ( 700 bar).

HO CH2 CH2 O C CH2 C O CH2 CH2 O C CH CH C O

4
O O O O

peroxide,
heat,

VPADME

HO CH2 CH2 O C CH2 C O CH2 CH2 O C CH CH C O

4
O O O O

EMDAPV

Figure 3.18 : VPADME grafting on unsaturated polyester polyol.

Other Mixture Polyols

3.8.1 Dopo - maleic anhydride reaction

50 mL 3-necked flask DOPO ( 0.2 mol; 43.2 g ) is loaded . On 60 g of toluene was

added. Temperature of 80oC is brought, and N2 is fed to the system. In 45-60 min
dissolution is complete. Maleic anhydride dissolved in THF by addition funnel over
60 g ( 0.2 mole; 19.6 g) was added over 1 hour . With added color starts to turn yellow.
Additional finishes the reaction was terminated after 24 hours. After cooling to room
temperature the solvent is removed in rotary evaporator. Consistency of the obtained
resin is obtained slightly greenish substance. The resin obtained was washed with

54
water and oven and water is removed. Viscous liquids are solidified cooled to room
temperature.

The solids were pulverized and formed into a white powder.

3.8.2 Oxazolidine-diethyl phosphite reaction

Reaction of paraformaldehyde and diethanolamine is shown in Figure 3.19.

OH
HO
H2
HO C O H + HN
n
N

OH O
Paraformaldehyde Diethanolamine Oxazolidine
Figure 3.19 : Formation of oxazolidine.

Paraformaldehyde (3 mole, 105.3 g) and diethanolamine (3 mole, 315 g) are fed 3-

necked flask and start mixing at N2 atmosphere and room temperature. Set temperature
55 oC. The reaction is continued for 2 hours at this temperature. Then the temperature
is raised to 85 oC ( This step is very important.

The temperature is 105-115 oC product degradation is occured ) . Reaction carried out

under vacuum (3,5-4 hour) than vacuum is terminated when humidity reaches 0.5-1.0
ppm. Reaction of oxazolidine with DEP is shown in Figure 3.20.
OH
HO O OEt EtO O
N
+ H P P CH2 N
O OEt EtO

OH
Oxazolidine Diethyl Phosphite
Figure 3.20 : Reaction between oxazolidine and diethyl phosphite.

3-necked flask was fed oxazolidine. Diethyl phosphite is added at 35 oC in 0.5 - 1

hour. After the addition was finished the temperature is raised to 50°C .

After waiting for half an hour at 50 °C temperature is increased to 115 o

C. Color
change will be observed over time ( first bright yellow , then brown shiny). 1.5 – 2
hours OH, acid, moisture, refractive index and GC-MS analysis is performed and the
reaction is terminated.

55
 Synthesize Biobased Synthetic Leather

Four necked flask was charged with 14.5 g, pripol 2033, 25.1 g monomeric mdi , 8.4
g 1,4-butanediol , 83.10 g toluene and 83.10 g DMSO heated to 60 oC while stirring.
1 hour later 6 g MDI added then viscosity of the mixture start to increase. When
viscosity of the reaction reached 20,000 cps at 60 oC. Isopropyl alcohol added and
temperature of the resin decreased at 25 oC. ( Polyol / Chain extender / MDI - 1 / 3 /
4)

Pripol 2033; (Dimerized linoleic acid based polyol): OH Value: 196 mgKOH/g,
Acidiy: 0,2 mgKOH/g, Mw: 570 Dalton, Viscosity: 2200 cps, Renewable % Carbon:
100. And the reaction is shown in Figure 3.21. Also molar ratio of poliol, diol and
isocyanate given in Table 3.3.
O O O

HO R R
O O R O R OH

H
O C N N C O
H

O
O O O O
H H
O C N C O R R
N O O R O R O C NH N C O
H H H
OH
HO

O O O O
O O
H H H H H H
O C N H H O
N C O C N C O R R O C NH N C O C NH N C O
H H O N O H
H H H
O O O
3

Figure 3.21 : Synthesize polyurethane.

Table 3.3 : Molar ratio of natural oil based polyol (Diol) / 1,4 butane diol /
monomeric MDI.
Product Name Natural Oil 1,4 Butane Isocyanate
Based Polyol Diol
Nat Pu 1 1 3 4
Nat Pu 2 1 5 6
Nat Pu 3 1 7 8
Nat Pu 4 1 9 10
Nat Pu 5 1 11 12
Nat Pu 6 1 13 14

56
 RESULTS AND DISCUSSION

Polyurethane From Styrene Grafted Polyols

Grafting of styrene on polyester polyols were carried out with a number of different
conditions to find the best product. Increasing styrene content results increasing
product yield but the grafting efficiency is not effected. Amount of open cell increase
related to amount of styrene increased.

4.1.1 Synthesis of polyester polyol

The product of polyester polyol is given in Figure 4.1.

Figure 4.1 : Polyester polyol.

Polyester polyol properties; OH number: 63 mg KOH/g, acidity: 0.5 mg KOH/g,

viscosity: 750 cPs. FTIR of polyester polyol is shown in Figure 4.2.

100
3523.88

90
2953.59

80
1451.56

422.66

70
1382.04

865.94

60
963.10

470.23
%T

1417.59

50
499.58

40
1063.06

30

20
1134.34
1724.83

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.2 : FTIR of saturated polyester polyol.

57
4.1.2 Grafting styrene on saturated polyester polyol

Composition percentage and parameters of grafting styrene on polyester polyol is

shown in Table 4.1

Table 4.1 : Grafting styrene on polyester polyol.

Polyester Theotrical
Polyester
Polyol OH OH Number Graft Polyol
Number of Polyol % Styrene Viscosity
[M]/[I] Number (mg KOH/g) OH Number
Experiment Viscosity Monomer (cP)
(mg (mg KOH/g)
(cP)
KOH/g)
1 1000/1 63 360 6 1255 59 60
2 1000/1 63 360 9 1637 57 57
3 1000/1 63 360 12 1825 55 55
4 1000/1 63 360 15 2320 53 49
5 1000/2 63 360 6 1100 59 59
6 1000/2 63 360 9 1470 57 58
7 1000/2 63 360 12 1580 55 55
8 1000/2 63 360 15 2210 53 51
9 1000/4 63 360 6 1050 59 59
10 1000/4 63 360 9 1380 57 57
11 1000/4 63 360 12 1600 55 54
12 1000/4 63 360 15 2185 53 52

FTIR spectrum of product is shown in Figure 4.3.

100
3531.27

90
2953.51

80
755.40
1451.79

419.13

70
498.04
868.29
1381.65

698.13

60
964.64
%T

50
1063.57

40

30

20
1136.94
1726.05

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.3 : FTIR of styrene grafted (%12) saturated polyester polyol.

58
4.1.3 Synthesize of unsaturated polyester polyol

Unsaturated polyester polyol is shown in Figure 4.4 and also properties of unsaturated
polyester polyol is listed in Table 4.2. FTIR spectrum of this polyol is given in Figure
4.5.

HO CH2 CH2 O C CH2 C O CH2 CH2 O C CH CH C O

4
O O O O

Figure 4.4 : Unsaturated polyester polyol.

Table 4.2 : Unsaturated polyester polyol properties.

Produc Amoun Acidity OH Viscosity Vacuum Side
t Code t (kg) (mg (mg (cP) (75 Duration Product
KOH/g) KOH/g) °C) (Hour) (g)
MD-1 16 0,67 64 520 05:30 1700
MD-2 15 0,51 85 440 06:00 1630
MD-3 17 0,41 75 480 06:00 1800
MD-4 17 0,37 57 570 06:00 1800

100
3525.98

90

80
2949.83

581.61
754.02
1418.08

438.55
70
1381.00

871.31
954.30

60
1455.01

500.01
%T

50

40
1077.92

30
1166.94

20
1126.97
1725.81

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( cm- 1)

Figure 4.5 : FTIR of unsaturated polyester polyol.

59
4.1.4 Styrene grafting on unsaturated polyester polyol

The formation of styrene grafted polyester polyol from styrene and polyester poliol in
presence of peroxide catalyst is shown in the Figure 4.6.

Figure 4.6 : Styrene grafted polyester polyol.

Properties of styrene grafted unsaturated polyester polyols are shown in Table 4.3.

Table 4.3 : Styrene grafted unsaturated polyester polyol properties.

Theotrical Graft Polyol
Number of OH Number Viscosity % Styrene Viscosity OH Number OH Number
[M]/[I]
Experiment (mg KOH/g) (cP) (75 °C) Monomer (cP) (75 °C) (mg KOH/g) (mg KOH/g)

1 1000/1 70 640 6 590 66 69

2 1000/1 70 640 9 957 64 65
3 1000/1 70 640 12 1020 61 58
4 1000/1 70 640 15 1480 59 55
5 1000/2 70 640 6 495 66 66
6 1000/2 70 640 9 750 64 60
7 1000/2 70 640 12 840 61 58
8 1000/2 70 640 15 1220 59 53
9 1000/4 70 640 6 440 66 67
10 1000/4 70 640 9 690 64 63
11 1000/4 70 640 12 730 61 60

12 1000/4 70 640 15 970 59 57

60
The final product styrene (%12) grafted polyester polyol’s FTIR spectrum is shown in
Figure 4.7.

100

90

80

29 49.47

43 4.85
75 5.08
14 52.96
70

13 80.88

87 0.74

69 8.66
95 4.29
60

49 9.34
%T

14 18.10
50

40

10 78.04
11 67.08
30

20

11 27.35
10 17 26.84

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( cm- 1)

Figure 4.7 : FTIR of styrene (%12) grafted unsaturated polyester polyol.

FTIR spectrums of unsaturated polyester polyol, styrene grafted unsaturated polyester

polyol, styrene grafted polyester polyol are shown together in Figure 4.8.

100

95

90

85

80

75

70

65
%T

60

55

50

45

40

35

30

25

20

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.8 : FTIR Comparision of unsaturated polyester polyol, styrene grafted

unsaturated polyester polyol, styrene grafted polyester polyol.
61
The amount of styrene used for grafting is limited since some agglomeration starts
during the polymerization. The final product is probably a mixture of polyester polyol,
grafted polyester polyol and polystyrene homopolymer and the mixture is in the form
of micoemulsion due to surfactant effect of initial polyol.

The foam samples produced from styrene grafted poylester polyols are compared with
the foam produced from polyester polyols under the same conditions. As seen in the
pictures in appendices section, foam produced from styrene grafted poylester polyols
is much more stable and has much lower shrinkage value.

Synthesis of Fire Retardant Modified Ketonic Resins

4.2.1 Kabachnik-Fields reaction of cyclohexanone- formaldehyde resin (CF-

Resin) with diethyl phosphite (DEP) and ethanolamine

Blank experiments of the reaction (Figure 4.9) of cyclohexanone with a mixture of

DEP and ethanolamine was carried out as described earlier (34,35). This method was
modified for the Kabachnik-Fields reaction between CF-R and the mixture of DEP and
ethanolamine. The product has low carbonyl peak intensity at about 1700 cm-1
compared to the peak of CF-Resin as seen ATR-FTIR spectra in the Figure 4.10 and
Figure 4.11. As expected that the conversion of the carbonyl group of CF-Resin is not
completed. The conversion was also calculated from phosphorous contents measured
by microanalysis. Since the material is not burning well, microanalysis results of
carbon, nitrogen were lower than theoretical values. 1H NMR, C-13 NMR, P-31 NMR
spectrum of modified resins are shown in the Figure 4.12, Figure 4.13, Figure 4.14.

Figure 4.9 : Diethyl phosphite and ethanolamine reaction.

62
Figure 4.10 : FTIR spectrum of CF-Resin.

Figure 4.11 : FTIR of CFR+EA+DEP.

63
Figure 4.12 : 1H NMR of CFR+EA+DEP.

Figure 4.13 : C-13 NMR of CFR+EA+DEP.

64
 Figure 4.14 : P-31 NMR of CFR+EA+DEP.

4.2.2 Kabachnik-Fields reaction of methyl ethyl ketone-formaldehyde resin

(MEKF-Resin) with DEP and ethanolamine

The kabachnik fields reaction between MEK resin, DEP and etanolamin is shown in
Figure 4.15.

Figure 4.15 : Methyl ethyl ketone-formaldehyde resin (MEKF-Resin) with diethyl

phosphite and ethanolamine.

Kabachnik-fields reaction product between MEKF-R and ethanolamine and phosphite

compound was also characterized by FTIR (Figure 4.16), microanalysis and NMR
techniques. The conversion of carbonyl groups was much lower than model

65
compounds. 1H NMR, C-13 NMR, P-31 NMR spectrum are shown in the Figure 4.17,
the Figure 4.18 and the Figure 4.19.

10
0 3414,3
1275,6
73409,3
2928,4 1454,2 3
9 0
9 3
1660,6 1376,2
5
1 0 1096,4
9 7
0 1703,9
2972,3 7 1376,2
8 8 2932,5 1663,0 1455,82 1163,9 764,5
5 0 4 9 4 7

8
0

7 1704,9
9
%T 5
1098,3
7 9 1076,0
0 1252,8 3
9
6
5

6
0 1042,5
8
5
5

5
0

4
5
4 ,9
1
4000, 360 320 280 240 200 180 160 140 120 100 80 650,
0 0 0 0 0 0 0 0 0 0 0 0 0

Figure 4.16 : FTIR comparison of MEK-F resin and modified MEK-F resin.

Figure 4.17 : 1H NMR of MEK-FR+EA+DEP.

66
Figure 4.18 : C-13 NMR of MEK-FR+EA+DEP.

Figure 4.19 : P-31 NMR of MEK-FR+EA+DEP.

67
Carbon, hydrogen, nitrogen and phosphorus content of modified resins is given in
Table 4.4.

Table 4.4 : Microanalysis result of modified ketonic resins.

No Sample C (%) H (%) N P (%)
(%)
Cyclohexanone –formaldehyde
CFR- resin modified with ethanolamine 51.45 8.71 6.02 5.38
DEP 1 (53.6)* (8.9) (4.8) (10.6)
+ diethyl phosphite(CFR-DEP)
Cyclohexanone –formaldehyde
resin modified with ethanolamine
CFR- 52.1 8.36 5.47 4.74
DEP 2 + diethyl phosphite(CFR-DEP) (53.6) (8.9) (4.8) (10.6)

Methyl ethyl ketone-

formaldehyde resin modified with
MEKR- 50.9 8.74 2.85 4.28
DEP ethanolamine + diethyl phosphite (49.8) (9.05) (5.28) (11.7)
(MEKR-DEP)
Methyl ethyl ketone-
formaldehyde resin modified with
MEKR- 63.5 7.34 2.72 3.32
DPP ethanolamine + diphenyl (56.5) (6.6) (3.8) (8.5)
phosphite (MEKR-DPP)
*Values in the paranthesis are theoretical values calculated from 100% conversion product.

4.2.3 Kabachnik-Fields reaction of acetophenone-formaldehyde resin (AF-

Resin) with DEP and ethanolamine

Reaction of acetophenone resin with DEP and ethanolamine is shown in Figure 4.20.

Figure 4.20 : Modification reaction of AF-Resin with ethanol amine and

diethylphosphite.

The product has low carbonyl peak intensity at about 1700 cm-1 compared to the peak
of AF-Resin as seen ATR-FTIR spectra in the Figure 4.21. The conversion of the

68
carbonyl group of AF-Resin is not completed. Kabachnik-Fields reaction of
acetophenone needs higher temperature and longer time. Decreasing of carbonyl peak
can be observe in Figure 4.22, Figure 4.23, Figure 4.24. Mg (ClO4)2 may increase the
reaction rate. The reaction of AFR with ethanolamine and diethyl phosphite was
carried out at comparably higher temperature in the presence of Mg(ClO4)2 and
Na2SO4 at different reaction times. However, after 6h reaction time, the yield was not
changed significantly. 1H NMR, C-13 NMR, P-31 NMR and FTIR spectrum of
modified resins are shown in the Figure 4.25, Figure 4.26, Figure 4.27, Figure 4.28.

Figure 4.21 : FTIR of AF resin.

Figure 4.22 : FTIR of AFR+EA+DEP purified and dried (1).

69
 Figure 4.23 : FTIR of AFR+EA+DEP (2).

Figure 4.24 : FTIR of AFR+EA+DEP purified and dried (3).

70
Figure 4.25 : 1H NMR of AFR+EA+DEP purified and dried.

Figure 4.26 : FTIR of DiCAF-Resin.

Figure 4.27 : FTIR of DiCAFR+EA+DEP.

71
 Figure 4.28 : 1H NMR of DİCAFR+EA+DEP.

Solubilities of the modified resins at room temperature are shown in Table 4.5.

Table 4.5 : Solubility of the modified resins at room temperature.

Resin CH2Cl2 toluene asetone metanol THF

Acetophenone-formaldehyde resin
+ + + - +
(AF-R)
Acetophenone-2,4-
dicholoroacetophenone- + + + + +
formaldehyde resin (DiCAF-R)

Acetophenone-formaldehyde resin
modified with ethanol amine + slightly + slightly +
+diethylphosphite (AFR.EA.DEP)

Acetophenone-formaldehyde resin
modified with ethanol amine
+diphenylphosphite + - + - +
(AFR.EA.DPP)
(catalyst:Mg(ClO4)2)
Acetophenone and 2,4-
dicholoroacetophenone
formaldehyde resin (DiCAF-R)
+ slightly slightly + +
modified with ethanol
amine+diethylphosphite
(DiCAFR.EA.DEP)
Acetophenone-formaldehyde resin
modified with ethanol amine
+ - - + +
+diphenylphosphite
(AFR.EA.DPP) (catalyst:Na2SO4)
+: soluble, -: insoluble at room temperature

72
TGA analysis of modified acetophenone-formaldehyde and 2,4-dichloro
acetophenone-formaldehyde resins are shown in the Figure 4.29, Figure 4.30, Figure
4.31, Figure 4.32, Figure 4.33, Figure 4.34. Resin are listed as follows:

Modified AF-F Resins (AD);

 AD1: AF-F Resin (reference)

 AD2: AF-Dichloroacetophenone-formaldehyde resin

 AD3: AF-F Resin + Ethanolamine+DEP

 AD4: AF-F Resin + EA+ DEF + 4 times perchlorate + DCE 24 hour

 AD5: AF- Dichloroacetophenone- formaldehyde Resin + Ethanolamine+DEP

 AD6: AF-F Resin +EA+Diphenylphosphite (DPP)

100.0
101.2%

90.0

80.0

70.0

60.0

TG %
50.0

40.0

30.0

20.0

10.0

0.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0

Temp Cel

Figure 4.29 : TGA analysis of AF Resin (AD1).

100.0

98.6%
90.0

80.0

70.0

60.0
TG %

50.0

40.0

30.0

20.0

10.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.30 : TGA analysis of DİCAF Resin (AD2).

73
 100.0

82.3%
90.0

80.0

70.0

TG %
60.0

50.0

40.0

30.0

20.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.31 : TGA analysis of AFR+EA+DEP (AD3).

100.0

71.9%

90.0

80.0

70.0

TG %
60.0

50.0

40.0

30.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.32 : TGA analysis of AFR+EA+DEP (AD4).

100.0
81.1%

90.0

80.0

70.0
TG %

60.0

50.0

40.0

30.0

20.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.33 : TGA analysis of DİCAFR+EA+DEP (AD5).

74
 100.0
85.0%

90.0

80.0

70.0

60.0

TG %
50.0

40.0

30.0

20.0

100.0 200.0 300.0 400.0 500.0 600.0

Temp Cel

Figure 4.34 : TGA analysis of AFR+EA+DEP (AD6).

4.2.4 Fire retardant polyurethane production using fire retardand modified

ketonic resins containing halogen, phosphorous and nitrogen

4.2.4.1 Polyuretane produced using fire retardant modified CF-resin and MEK-
F resin

Modified CF-R and MEKF-R were mixed with polyol used for rigid PU formulations.
The amount of modified resin was in the range of 10-25 % of polyol. TGA shows an
increase in the residue at the temperature of 5500C in Figure 4.35, Figure 4.36, Figure
4.37, Figure 4.38, Figure 4.39. Foam production formulation:

12.5 g Modified resin (AD) + 12.5 g DCM + 25 g Polymix + 72 g NCO

DTG ug/min

DTA uV

TG %

Figure 4.35 : TGA analysis of CFR in polyurethane foam.

75
DTG ug/min

DTA uV

TG %
Figure 4.36 : TGA analysis of 10% CFR-EA-DEP at polyurethane foam.
DTG ug/min

DTA uV

TG %

Figure 4.37 : TGA analysis of 15% CFR-EA-DEP at polyurethane foam.

DTG ug/min

DTA uV

TG %

Figure 4.38 : TGA analysis of 20% CFR-EA-DEP at polyurethane foam.

76
DTG ug/min

DTA uV

TG %
Figure 4.39 : TGA analysis of 25% CFR-EA-DEP at polyurethane foam.

4.2.5 Polyurethane produced using modified AF-resin and DiCLAF- resin

TGA analysis of polyurethane which produced by using modified resins is shown in

Figure 4.40, Figure 4.41, Figure 4.42, Figure 4.43, Figure 4.44, Figure 4.45.

Foam using modified AF-F resins (AD);

 AD1 at foam: AF-F Resin (reference)

 AD2 at foam: AF-Dichloroacetophenone-formaldehyde resin

 AD3 at foam: AF-F Resin + Ethanolamine+DEP

 AD4 at foam: AF-F Resin + EA+ DEP + 4 times perchlorate + DCE 24 hour

 AD5 at foam: AF- Dichloroacetophenone- formaldehyde Resin +

Ethanolamine+DEP

140.0

120.0

100.0

98.9%

80.0

60.0
TG %

40.0

20.0

0.0

-20.0

-40.0
100.0 200.0 300.0 400.0 500.0 600.0 700.0
Temp Cel

Figure 4.40 : TGA analysis of AD1 at polyurethane foam.

77
 120.0

100.0
100.3%

80.0

60.0

TG %
40.0

20.0

0.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.41 : TGA analysis of AD2 at polyurethane foam.

120.0

100.0
84.6%

80.0

TG %
60.0

40.0

20.0

0.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.42 : TGA analysis of AD3 at polyurethane foam.

120.0

100.0
121.0%

80.0

60.0
TG %

40.0

20.0

0.0

-20.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.43 : TGA analysis of AD4 at polyurethane foam.

78
 120.0

100.0
92.9%

80.0

60.0

TG %
40.0

20.0

0.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.44 : TGA analysis of AD5 at polyurethane foam.

120.0

100.0

74.0%

80.0

TG %
60.0

40.0

20.0

100.0 200.0 300.0 400.0 500.0 600.0 700.0

Temp Cel

Figure 4.45 : TGA analysis of AD6 at polyurethane foam.

LOI results of AD products in foam listed in Table 4.6.

Table 4.6 : LOI results at AD products in foam.

Products at Foam Limiting Oxygen Index
AD1 20
AD2 22
AD3 22
AD4 23
AD5 22
AD6 21

79
Two foam samples that left side has not any flame retardant, right side include AD5 at
%20. At polymix ignite at same time. Right side foam is self- extinguished within 2
seconds. The left foam continues to fast burning. Picture of the this test shown at Figure
4.46.

Figure 4.46 : Foam flammability test (Left: without resin, Right: %20 AD 5 resin).

Fire Resistant Polyurethane Using THEIC-Tris (2-chloroethyl) Phosphite

Products

HO

OH
Cl

O N O
O
+ O O N O
Cl P Cl - ClC 2H5OH
N N
O
N N
O
HO OH
O
O
O OH
P
Cl O

Cl

Figure 4.47 : Reaction mechanism THEIC and tris(2-chloroethyl) phosphite.

The reaction product of the THEIC- Phosphite is slightly viscose liquid has the
following properties; viscosity: 2560 cP at 25°C; OH value: 314 mg of KOH/g. FTIR

80
spectrum of theic-tris(2-chloroethyl) phosphite product is shown in Figure 4.48. Also
FTIR of theic shown in Figure 4.49.

Figure 4.48 : FTIR of theic-tris(2-chloroethyl) phosphite product.

3000-3600 cm-1 : O-H stretching

2980-2900 cm-1 : Aliphatic C-H stretching

1678 cm-1 : C=O stretching of cyanuric acid ring

1015 and 901 cm-1 : P-O stretching

800-600 cm-1 : C-Cl stretching (especially 659 cm-1)

Figure 4.49 : FTIR of THEIC.

81
TGA of TCPP and theic-tris(2-chloroethyl) phosphite product is shown in the
Figure 4.50 and the Figure 4.51.

Figure 4.50 : TGA of TCPP.

Figure 4.51 : TGA result of theic-tris(2-chloroethyl) phosphite product.

Polymix formulation is listed in Table 4.7.

Table 4.7 : Polymix formulation.

Polymix Formulation Mass Concentration (%)
Polyether polyol 91,1
Silicone 2
Pentane 0,7
Water 3
Catalyst 3,2

82
Table 4.8 and Table 4.9 polymix containing different amount of flame retardants and
foam properties.

Table 4.8 : Polymix with different amount of flame retardants and foam properties.
D 1 D 2 D 3 D 4 D 5 D 6 D 7 D 8 D 9 D 10 D 11
Polymix (g) 85 80 75 70 80 75 70 65 75 70 65
THEIC-
10 10 10 10 15 15 15 15 20 20 20
Phosphite (g)
TCPP (g) 5 10 15 20 5 10 15 20 5 10 15

Mixing Time
6 6 6 6 6 6 6 6 6 6 6
(s)
Cream Type
11 11 9 9 10 11 9 9,5 10 10 10
(s)
Gel Time (s) 30 30 28 27 28 28 27 27 27 27 28
Tack Free
38 38 36 36 35 36 35 34 35 34 35
Time (s)

Table 4.9 : Polymix with different amount of flame retardants and foam properties.
D 12 D 13 D 14 D 15 D 16 D 17 D 18
Polymix (g) 60 90 85 80 90 85 80
THEIC- Phosphite
20 10 15 20 0 0 0
(g)
TCPP (g) 20 0 0 0 10 15 20

Mixing Time (s) 6 6 6 6 6 6 6

Cream Type (s) 10 10 11 11 10 10 9
Gel Time 26 31 34 36 32 32 28
Tack Free Time (s) 34 40 44 49 43 42 37

Results of horizontal test chamber are shown in Figure 4.52.

Figure 4.52 : Picture of horizontal test chamber results.

When examined Table 4.8 and Figure 4.52 it is clearly seen that THEIC-Phosphite fire
retardant compound can be used in place of TCPP in polyurethane rigid foam. The
experiment of D15 and D18 shown that foam forming properties didn’t change ( cream

83
time, gel time and tack free time). TGA results of theic-tris(2-chloroethyl) phosphite
product and TCPP are shown in the Figure 4.53 and the Figure 4.54.

Figure 4.53 : TGA result of theic-tris(2-chloroethyl) phosphite (18 % at polymix) at

foam.

Figure 4.54 : TGA result of TCPP (18 % at polymix) at foam.

Fire Resistant Polyurethane From THEIC-TCPP Products

4.4.1 Formation of THEIC-TCPP products

In the classical transesterification reaction, THEIC reacts with TCPP by the help of
transesterification catalyst such as dibutyltin diluarate followed by elimination of 1-
chloropropan-2-ol which is removed by vacuum distillation. Possible mechanism of
the formation of the product (FR-1) from 1 mol of THEIC and 2 moles of TCPP is
shown in the Figure 4.55

84
 Cl

O
O P O
Cl
OH O
O O
HO HO Cl
Cl
N N O Catalyst N N
+ P
O
+
O N O O O N O
O HO
Cl

OH O Cl
Cl O
P
O
O

Cl

Figure 4.55 : Formation of FR-1.

Theic and tcpp reactions were performed in 1:1, 1:2, 1:3 and 1:5 molar ratios. The
reaction conditions and yields are summarized in Table 4.10. Distilled products were
analyzed by GC-MS and found that they are a mixture of 1-chloropropan-2-ol and
excess tcpp. As seen from the Table 4.10, increasing initial tcpp content results
increasing distilled product.

Table 4.10 : Theic-tcpp reaction condition.

T:T(1:1) (g) T:T(1:2) (g) T:T(1:3) (g) T:T(1:5) (g)

THEIC 169,65 104,4 104.4 104,4

TCPP 212.94 262,08 393.12 655,2

Distilled
3 15 29 56
Products (%)

Time (h) 18 16 14 14

Hydroxyl, acid and viscosity values of obtained products are shown in Table 4.10.

Polycondensation reaction also occurs as a side reaction between theic and tcpp when
the molar ratio of tcpp decreases Figure 4.56. As a result, viscosity increases
excessively. Generally low viscosity is desirable for polyurethane applications
especially in rigid foam application. Viscosity and OH value decrease when 1:5 molar
ratios are used. In this case, the possibility of bounding FR molecules to the
polyurethane structure is low because of its low hydroxyl value.

85
 Cl
OH
O
HO
N N O Catalyst
+ P
O
O N O O
O
Cl

OH
Cl

OH

O N O O
O O
O O
N N P N N P
O O
O O
O O N O Cl
HO
Cl
n Cl
OH

Figure 4.56 : Polycondensation of THEIC and TCPP.

Trials have been performed on rigid polyurethane foam systems where both FR-1 and
FR-2 used as fire resistant. Fort the application, including FR at different ratios and
not including FR foams are prepared. Only FR and the ratio have been changed during
the formulation. Quality control test results are given in the Table 4.11.

Table 4.11 : THEIC-TCPP quality control test results.

Distiled
Product THEIC:TCPP OH content Acid content Viscosity
Product
code molar ratio (mg KOH/g) (mg KOH/g) (25 °C) (cP)
(g)

FR 1:1 74 11 950 3

FR-1 1:2 146 12 1250 15

FR-2 1:3 90 25 250 29

FR-3 1:5 55 26 55 56

4.4.2 Characterization of FR obtained from THEIC and TCPP

FTIR of fire retardants (FR) are shown in the Figure 4.57, Figure 4.58, Figure 4.59,
Figure 4.60, Figure 4.61, Figure 4.62, Figure 4.63, Figure 4.64, Figure 4.65, Figure
4.66, Figure 4.67. The absorptions of –CH3 and –CH2– were observed at 2975–2920
cm-1, and the absorption of –C-N-C was at 1453 cm-1. A broad absorption band at
3600-3400 cm-1 due to O–H stretching. The peaks at 1261 and 990 cm-1 are due to the

86
P=O and P–O–C in the phosphate, respectively. The strong band at 1685 cm-1 clearly
indicates the C=O stretching frequency of theic. Furthermore, the C-Cl stretching was
at about 760 cm-1.

Figure 4.57 : FTIR spectrum of TCPP.

Figure 4.58 : FTIR spectrum of THEIC.

100

95

90

85

80

75

70

65

60
%T

55

50

45

40

35

30

25

20

15

10
400 0 350 0 300 0 250 0 200 0 150 0 100 0 500
W av enu mber s ( c m- 1)

Figure 4.59 : FTIR spectrum of THEIC + TCPP (1:1) (FR).

87
 100

95

90

85

80

75

70

65

60
%T

55

50

45

40

35

30

25

20

15

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.60 : FTIR spectrum of THEIC + TCPP (1:2) (FR-1).

Figure 4.61 : Phosphorus NMR spectrum of FR-1.

Figure 4.62 : 1H NMR spectrum of FR-1.

88
 100

95

90

85

80

75

70

65

60

%T
55

50

45

40

35

30

25

20

15

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.63 : FTIR spectrum of THEIC + TCPP (1:3) (FR-2).

Figure 4.64 : 1H NMR spectrum of (FR-2).

Figure 4.65 : P-31 NMR spectrum of (FR-2).

89
 100

95

90

85

80

75

70

65

60
%T

55

50

45

40

35

30

25

20

15

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.66 : FTIR spectrum of THEIC+TCPP (1:5) (FR-3).

100

95

90

85

80

75

70

65

60
%T

55

50

45

40

35

30

25

20

15

10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure 4.67 : FTIR spectrum of all FR products.

[Purple (1:1); Blue (1:2); Red (1:3); Green (1:5)]

4.4.3 The flame retardant effect of FR products

4.4.3.1 Structure of the polyurethane containing flame retardant (FR)

FTIR spectrum of PUR-3 is shown in Figure 4.68.

Figure 4.68 : FTIR spectrum of PUR-3.

90
IR spectra of PU foam (PUR-3) shows broad bands around 3450-3310 cm-1 due to N-
H bond. The stretching absorption of –C-N 1405 cm-1 and the band 1701 cm-1 confirm
the presence of R-O-CO-N groups. The absorption bands around 2274 cm-1 show the
presences of terminal NCO groups in PU. The bands around 1217 cm-1 and 1067 cm-1
are due to P=O and P-O-C stretching frequencies respectively. Furthermore, the C-Cl
stretching was seen at about 755 cm-1.

4.4.3.2 The flame retardant effect of FR type and amount

Initial trials have been performed on rigid polyurethane foam systems where both FR-1
and FR-2 used as fire retardant reactive additive. For the application, including
polyurethane foam containing FR at different ratios and foam without FR were
prepared. Only FR and the ratio have been changed during the formulation. The
formulations are shown in the Table 4.12.

Table 4.12 : Polyurethane foam formulations.

Material PUR-1 PUR-2 PUR-3 PUR-4 PUR-5 PUR-6 PUR-7

Polyether polyol 100 100 100 100 100 100 100

Pentane 0,7 0,7 0,7 0,7 0,7 0,7 0,7

Tegostab B 8443 2 2 2 2 2 2 2

Distilled water 0,3 0,3 0,3 0,3 0,3 0,3 0,3

FR-1 - 5 10 15 - - -

FR-2 - - - - 5 10 15

Dabco TMR 1,5 1,5 1,5 1,5 1,5 1,5 1,5

PMDI 130 130 130 130 130 130 130

The larger value of LOI is, the harder it is for the material to catch fire and to burn.
Generally speaking, fort he case of oxygen index below 21, the material is considered
flammable; for oxygen index = 22-25, the material is self-extinguishable; and for the
case of oxygen index > 26, the material is hard to burn [8] To investigate the flame
retardancy of polyurethane foam, we tested the limiting oxygen index (LOI) of flame
retardant PUR systems with a 5 wt% - 10 wt% -15 wt% FR loading. As can be seen
from Table 4.12 with increases in FR content, the LOI values increase.

The highest LOI value is obtained with 15 wt% FR loading. As seen in the pictures
(appendices section) FR-2 is better fire retardancy property than TCPP alone at the
same concentration (20 %). LOI test results of polyurethane foam are shown in Table
4.13.

91
 Table 4.13 : LOI test results of polyurethane foam.
FOAM % FR LOI
PUR-1 0 15,5
PUR-2 5 22
PUR-3 10 24
PUR-4 15 25,5
PUR-5 5 21
PUR-6 10 23
PUR-7 15 23

4.4.3.3 Further studies on fire resistance polyurethane foam production

Further studies were carried out using formulation given in the table 4.13 to produce
fire resistance polyurethane foam. Physical properties including LOI values of these
produced fire resistance polyurethane foams were measured. Some new additives such
as DOPO, zinc borate were also included to improve fire resistance and smoke
suppressant properties of polyurethane. The results are summarized in the table 4.13.
In UL94 test method for the sample to get a V-0 rating it must self-extinguish within
10 s and there should not be any sign of dripping of burning polymer. If the sample
continuously burns or if it drips polymer, a V-1 or V-2 rating is given. For PU foams
UL94 results are shown in Table 4.14.

Table 4.14 : Flammability properties comparison dopo and zinc borate with FR
products in foam.
Thermal Compressive
Density
Foam Conductivity Strenght at LOI UL 94
(kg/m3)
(W/m K) % 10 (kPa)
TCPP (%23) 31 0,02652 185 24 V0
THEİC-TCPP
34 0,02788 325 24 V0
(1:1) (%23)
THEIC-TCPP
36 0,02835 276 25 V0
(1:2) (%23)
THEIC-TCPP
33 0,02647 250 25 V0
(1:3) (%23)
THEİC-TCPP
33 0,02754 195 25 V0
(1:5) (%23)
DOPO (% 23) 30 0,04834 105 19 V2
THEIC-
TCPP(1:5)-
32 0,03395 130 22 V1
10+DOPO-5
(%23)
THEIC-
TCPP(1:5)-
30 0,04256 100 21 V1
5+DOPO-10
(%23)
Zn(BrO3)2 33 0,02787 85 18 V2
THEIC-
TCPP(1:5)-5+
31 0,02821 150 22 V1
Zn(BrO3)2-10
(%23)
THEIC-
TCPP(1:5)-10+
35 0,02767 125 19 V1
Zn(BrO3)2-5
(%23)

92
4.4.3.4 TGA results of THEIC-TCPP products

The TGA is one of the commonly used techniques for rapid evaluation of thermal
stability of different materials, and can also indicate the decomposition behavior of
polymers at various temperatures.

The TGA measurements were performed under a nitrogen atmosphere with a heating
rate of 10 ˚C min-1, 30 ˚C to 500 ˚C and 800 ˚C. TGA analysis was performed on
liquid FR, FR-1, FR-2, FR-3 samples and foams containing reactive fire retardants of
FR, FR-1, FR-2, and FR-3. And results are given in Figure 4.69 and Figure 4.70.

Figure 4.69 : TGA result of flame retardant products.

1 : Black : TCPP

2 : Blue : THEİC+TCPP 1/1

3 : Green : THEİC+TCPP ½

4 : Turqoise : THEİC+TCPP 1/3

5 : Pink : THEİC+TCPP 1/5

93
 100.0
74.5%
77.5%
99.7% 74.3%
78.9%
90.0

80.0

70.0

60.0

50.0
DTG ug/min

DTA uV

TG %
40.0

30.0

20.0

10.0

0.0

-10.0

50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 450.0

Temp Cel

Figure 4.70 : TGA result of flame retardant products at polyurethane foam.

Black: TCPP

Turqoise:THEİC+TCPP 1/1

Blue:THEİC+TCPP 1/2

Green: THEİC+TCPP 1/3

Pink:THEİC+TCPP 1/5

Fire Resistant Polyurethanes From Mixture of Polyols

a) Cyanuric acid-formaldehyde condenzation product:

Reaction of cyanuric acid and 3 mol formaldehyde is shown in Figure 4.71.

O OH O
O
HN NH N OH
3 N
+ H H
O O O
N O N
H
HO
Figure 4.71 : Cyanuric acid and formaldehyde reaction mechanism.

This trimethylol cyanuric acid was added into polyol component with 5% and 20%
weight ratios and the produced rigid PU foam was tested with UL94. 20% addition of
trimethylol isocyanurate showed considerable fire retardant effect and the product has

94
V-0 value in UL-94. However, Foam production was not appropriate if its addition
value is 20%. So this product, alone, is not suitable as fire retardant for rigid PU foam.

b ) Cyanuric acid-formaldehyde-diethanol amine condenzation product:

Mannich base produced from isocyanuric is shown in Figure 4.72.

Figure 4.72 : Mannich base with isocyanuric reaction.

This product was tested in textiles and showed some fire retardancy effect. However,
its fire retardancy is not very satisfactory. This compound should be mixed some
strong fire retardant compounds containing phosphorus and boron.

a) Formation of methyl ethyl keton-melamine formaldehyde resin is shown in

Figure 4.73.

Figure 4.73 : Methyl ethyl keton-melamine formaldehyde reaction.

95
Melamine content of this resin should be below 15% otherwise some precipitation
forms during resin production. The resin containing 15% melamine is not very
efficient fire retardant.

Fire Resistant Polyurethanes From Vinyl Phosphonate Grafted Polyols

Vinyl phosphonic acid dimethylester was grafted onto unsaturated polyester

synthesized in section 3.3.3 (see also section 4.1.3) using different radical initiators
(Table 4.15). Besides, both vinyl phosphonic acid dimethylester and hydroxyl butyl
acrylate were grafted together.

The properties of grafted polyester polyols are shown in the Table 4.15 and Table 4.16.
These grafted polyol were used for rigid polyurethane foam production as explained
in the section 3.5.1. FTIR spectrum of vinyl phosphonic acid dimethyl ester grafted
polyol is shown in Figure 4.74.

Figure 4.74 : FTIR of vinyl phosphonic acid dimethyl ester grafted polyol (1: inıtial
mixture, 2: one hour polymerization time, 3 : final grafted product).

96
 Table 4.15 : VPADME grafting on unsaturated polyester.
Unsaturated (Polyol-22) (Polyol 33)
polyester (PVPADME+ PES+VPADME+
polyol PES+AIBN) HBA+ TBHP
Grafting conditions
Polyol (g) - 90 1921
136g +144 g
VPADME(g) - 20,4 HBA
Temperature 120
(C) - 150
Properties of polyols
OH (mg 83
KOH/g ) 70 67,13
Viscosity 872
cps) 640 1730 (50)
Acidiy 0,5 1,61 0.79
Hummidty 0,055
(%) 0,04 0,079

The produced polyurethane foam products were tested with TGA and UL 94. The
results were shown below. These results suggest that the polyurethane foams produced
from both VPADME and VPADME+HBA grafted PES polyols show fire retardancy
properties.

Table 4.16 : Properties of polyurethane produced VPADME and HBA grafted

polyester polyol.
PES+VPADME PES+VPADME+HBA
UL 94 9.5 9
(reference: 9.5
cm max)

TGA of PU foam from polyester grafting with VPADME and different intiators is
shown in Figure 4.75 and Figure 4.76.
4.000

550.0
3.500
500.0 3.000

450.0 3.000

2.000
400.0
2.500
350.0
DTG ug/min

1.000
DTA uV

TG mg

300.0 2.000

250.0 0.000
1.500
200.0

-1.000
150.0 1.000

100.0
-2.000 0.500
50.0

0.0
100.0 200.0 300.0 400.0 500.0
Temp Cel

Figure 4.75 : TGA of Pu foam from polyester grafting with VPADME and BP for
initiator.

97
 1.200 4.000
7.000

3.000
1.000 6.000

2.000

5.000
0.800

1.000
DTG mg/min

DTA uV

TG mg
4.000
0.600
0.000

3.000
-1.000
0.400

2.000
-2.000

0.200

-3.000 1.000

100.0 200.0 300.0 400.0 500.0

Temp Cel

Figure 4.76 : TGA of Pu foam from polyester grafting with VPADME and AIBN
for initiator.

Synthesis of Synthetic Leather Polyurethane From Biobased Polyol

In Figure 4.77, polyurethane synthesis for synthetic leather is shown. The product
which is synthesized by using the polyol, diol and MDI in different ratios analyzes by
using FTIR spectroscopy. Results are shown in Figure 4.78, Figure 4.79, Figure 4.80,
Figure 4.81, Figure 4.82, Figure 4.83 and Figure 4.84. FTIR bond streching values are
shown in Table 4.17.
O O O

HO R R
O O R O R OH

H
O C N N C O
H

O
O O O O
H H
O C N C O R R
N O O R O R O C NH N C O
H H H
OH
HO

O O O O
H H H H O
HO C N C O R R O CNH N C OH
O H N O
H H
O
3

H
O C N N C O
H

O O O O O
H H H H H H O H
OCN NC O C N C O R R O CNH N C O CNH NCO
H O H N O H
H H
O O
3

OH

H3C CH3

O O O O
O O
H H H H H H
O C N H H O
N C O C N C O R R O C NH N C O C NH N C O
H H O N O H
H H H
O O O
3

Figure 4.77 : Biobased solvent based polyurethane synthesis for synthetic leather.

98
Figure 4.78 : Nat Pu 1 – biobased polyol / 1,4 butanediol / MDI (1 / 3 / 4).

Figure 4.79 : Nat Pu 2 – biobased polyol / 1,4 butanediol / MDI (1 / 5 / 6).

Figure 4.80 : Nat Pu 3 – biobased polyol / 1,4 butanediol / MDI (1 / 7 / 8).

99
Figure 4.81 : Nat Pu 4 – biobased polyol / 1,4 butanediol / MDI (1 / 9 / 10).

Figure 4.82 : Nat Pu 5 – biobased polyol / 1,4 butanediol / MDI (1 / 11 / 12).

Figure 4.83 : Nat Pu 6 – biobased polyol / 1,4 butanediol / MDI (1 / 13 / 14).

100
 Figure 4.84 : FTIR comparision of all polyurethanes.

Table 4.17 : FTIR bond strechings.

Wavenumber Assignment
3446 st N-H (free)
3330 st N-H (bonded)
3000-2840 st C-H
2270 st N=C=O
1729 st C=O (free ester and urethane)
1707 st C=O (bonded ester and urethane)
1700-1690 st C=O (free urea)
1640 st C=O (bonded ordered urea)
1520 st C-N +  N-H
1475-1450  CH2
1450-1400 st sym (COO-)
1078 st sym N-CO-O + st (C-O-C)
954 st C-O-C

Stress strain tests are shown in Figure 4.85, Figure 4.86, Figure 4.87, Figure 4.88,
Figure 4.89, Figure 4.90.

Figure 4.85 : Stress strain test result of Nat Pu1.

101
Figure 4.86 : Stress strain test result of Nat Pu2.

Figure 4.87 : Stress strain test result of Nat Pu3.

Figure 4.88 : Stress strain test result of Nat Pu4.

102
 Figure 4.89 : Stress strain test result of Nat Pu5.

Figure 4.90 : Stress strain test result of Nat Pu6.

Mechanical properties of polyurethane products are given in the Table 4.18.

Table 4.18 : Summary of polyurethane mechanical properties.

Product Name

NatPu1 NatPu2 NatPu3 NatPu4 NatPu5 NatPu6

%100
Modulus 44,1 96,1 133,3 187,4 198,1 233,85
(kgf)
%200
Modulus 57 132,9 181,3 275,21 0 303,6
(kgf)
%300
Modulus 73,4 178,2 0 0 0 0
(kgf)
Elongation
at Break 388,8 311,5 271 238 201 190
(mm)
Load at
336 300 280 254 203 164
Break (kgf)

103
Abrassion test applied on Nat PU 1, Nat PU 2, Nat PU 3, Nat PU 4, Nat PU 5, and Nat
PU 6 leather and results are shown in Figure 4.91.

Figure 4.91 : Abrasion Test Results (Martindale at Leather).

104
 CONCLUSIONS

Polyols and styrene grafting; Polyester polyols were synthesized and used for rigid PU
production and microcellular elastomer for shoe sole application. These saturated
polyester polyols and unsaturated polyols were post modified by grafting styrene and
the modified poyester polyols were used to prepare PU with a more open cell structure.

Modifiying fire retardant additive of TCPP; TCPP, one of the most used fire retardand
for rigid PU, is a toxic organic compound and evaporates slowly from PU to
enviroment. TCPP was reacted with THEIC to produced new reactive liquid fire
retardands with better fire retardancy and much lower vapor pressure.

Synthesis of a new fire retardant from trichloro propyl phosphite and THEIC:

Trans esterification reaction between trichloro propyl phosphite and THEIC resulted
compounds containing both the ring of isocyanuric acid and dichloro propyl phosphite
moeity as well as reactive hydroxyl groups. These products showed rather good fire
retardand effect to rigid PU. However, the raw material, trichloro propyl phosphite is
difficult to find in the market.

Synthesis of new reactive fire retardands from keton-formaldehyde resin:

Carbonyl groups Ketonic resins such as MEK-formaldehyde, Cyclohexanone-

formaldehyde and acetophenone-formaldehyde resin were reacted with ethanolamine-
diethyl phosphite and ethanolamine-diphenyl phosphite to produce ketonic resins
containing both hydroxyl groups and phosphorous (Tri component Kabachnik-Fields
reaction). Adding these reactive resins into polyol component with 20-30% resulted
raher good fire retardand rigid PU foam with better physical properties. Grafting of
vinyl phosphonic acid dimethyl ester to unsaturated polyester polyols: Dimethyl vinyl
phosphonic acid were grafted by radical initiators such as AIBN and BP to polyester
polyols containing some unsaturation. 20-30 w % phosphonic monomers grafted
polyester polyols resulted good fire retardant rigid PU foam.

105
Mixture polyols; Polyols containing high percent of nitrogen and ring structure were
synthesized and used to produce rigid PU foam. However, their fire retardancy effect
were limited.

Biobased polyurethane was synthesized with different strenght for synthetic leather
application. DMSO-Toluene mixture is used instead of DMF because of DMF’s
solubility and toxic property.

Future works:

1) Organic and inorganic fire retardand compouds containing only phosphorous

atom will be tested.

2) Grafting of cheap monomers containing phosphorous to unsaturated polyester

with double bond in the side chain will be studied.

106
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Woods, G. (1987). The ICI Polyurethanes Book. ICI Polyurethanes. Wiley.
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New Horizons For Old Reaction. Arkivoc, 1(11), 1-17.

109
110
APPENDICES

100

90

2953.69
80

702.28
1417.63

418.97
500.51
70

864.41
1381.62
60

963.98

424.69
1451.50
%T

50

40

1063.48
30

20

1135.22
1725.16
10

0
400 0 350 0 300 0 250 0 200 0 150 0 100 0 500
W av enu mber s ( c m- 1)

Figure A.1 : FTIR spectrum of 6 % styrene grafted onto saturated polyester polyol

100

90
2953.89

80

701.16
1451.54

428.48
498.21
70
864.79
1381.46

60
964.61
%T

50

40
1063.41

30

20
1135.41
1725.20

10

0
400 0 350 0 300 0 250 0 200 0 150 0 100 0 500
W av enu mber s ( c m- 1)

Figure A.2 : FTIR spectrum of 9 % styrene grafted onto saturated polyester polyol

111
 100

3531.44
90

2953.28
80

755.43
1451.78

415.09
70

501.27
1348.11

865.29

698.34
60

964.67

421.96
%T

50

1381.53

1063.76
40

30

20

1135.75
1725.54
10

400 0 350 0 300 0 250 0 200 0 150 0 100 0 500

W av enu mber s ( c m- 1)

Figure A.3 : FTIR spectrum of 12 % styrene grafted onto saturated polyester polyol

100
3525.74

90
2953.50

80

700.09
1451.67

423.89
70

498.40
1348.08

866.71
60

964.79
%T

50
1381.52

40
1063.62

30

20
1135.48
1725.25

10

0
400 0 350 0 300 0 250 0 200 0 150 0 100 0 500
W av enu mber s ( c m- 1)

Figure A.4 : FTIR spectrum of 15 % styrene grafted onto saturated polyester polyol

Figure A.5 : GPC graph of 6 % styrene grafted onto saturated polyester polyol
112
Figure A.6 : GPC graph of 9 % styrene grafted onto saturated polyester polyol

Figure A.7 : GPC graph of 12 % styrene grafted onto saturated polyester polyol

113
Figure A.8 : GPC graph of 15 % styrene grafted onto saturated polyester polyol

114
Figure A.9 : TCPP (20 % in polymix) at polyurethane rigid foam (9 cm)

115
Figure A.10 : THEIC-TCPP (FR-2 20 % in polymix) at polyurethane rigid foam (8
cm)

116
 CURRICULUM VITAE

Name Surname : Başar Yıldız

Place and Date of Birth : İstanbul 1980

E-Mail : basaryildiz@gmail.com

EDUCATION

B.Sc. : ITU, Chemical Engineering

M.Sc. : ITU, Chemical Engineering

PROFESSIONAL EXPERIENCE AND REWARDS:

 2010 General Manager of Poliser

 2006 Factory and Marketing Manager of Poliser
 2005 Product Development Manager of Poliser
 2004 Product Development Engineer of Poliser
 2003 Asistant Product Manager of Flokser Group

PUBLICATIONS, PRESENTATIONS AND PATENTS ON THE THESIS:

 Yıldız B., Seydibeyoğlu M., Ö., Güner S., (2009). Polyurethane–zinc borate
composites with high oxidative stability and flame retardancy, Polymer
Degradation and Stability, 94(7), 1072-1075.
 Yıldız B., Seydibeyoglu M. Ö. and Güner S., The Anti-Oxidant Effect of
Zinc Borate on Polyurethane Films, Polychar-14, April 16-20, 2006, Japan.
 Önen D., Kızılcan N., Yıldız B., Akar A., (2015). Nano composite of clay
and modified ketonic resin as fire retardant polyol for polyurethane,
International Journal of Chemical, 1(2), 704.

117
118