Mechanical Properties, Morphology, and Crystallization

Behavior of Polypropylene/Elastomer/Talc Composites

Jyh-Horng Wu,1 Chien-Wen Chen,2 Yao-Tsu Wu,1 Guan-Ting Wu,2 M.C. Kuo,2 Yuh-sin Tsai3
1
Green Energy & Eco-Technology Center, Industrial Technology Research Institute, Tainan 70955, Taiwan, ROC

2
Department of Materials Engineering, Kun Shan University, Tainan 71003, Taiwan, ROC

3
School of Chinese Medicine, China Medical University, Taichung 40402, Taiwan, ROC

In this study, polypropylene/ethylene–octene copoly- increase the fractural toughness of the resulting PP blends.
mer (PP/POE) blends, PP/talc, and PP/POE/micro-talc Recently used to toughen PP, ethylene–octene copolymers
(MT) composites were fabricated using a twin screw.
To estimate the performances of the PP/POE blends,
(POE) demonstrate a high toughening efficiency and are
PP/talc, and PP/POE/MT composites, mechanical easier to process than EPDMs are [3, 13–16].
properties, heat deflection temperature (HDT), thermo- Yang et al. [17] fabricated a PP/POE (80/20) blend
mechanical analysis, and isothermal crystallization and reported that the notched Izod impact strength of the
characterization were conducted. Incorporating talc blend at 23 C was as high as 6.0 kJ/m2. They also
particles increased the tensile strength, flexural prop-
erties, and HDT of the PP matrix, but reduced the elon- observed brittle–ductile transition beh6avior during
gation at break and notched impact strength. The impact and high-speed tensile tests. Liang [2] found that
inclusion of POE elastomers in the PP matrix yielded Young’s modulus and tensile strength of the PP/POE
the opposite effect on PP/talc composites. PP/POE/MT blends declined nonlinearly with increases in the POE
composites provide a compromise that improves both weight fraction, whereas the V-notched impact fracture
the flexural properties and notched impact strength.
Moreover, the inclusion of talc particles in PP/POE strength increased nonlinearly with the POE weight frac-
blends induced heterogeneous nucleation and consid- tion. Tang et al. [3] melt-blended a polypropylene random
erably reduced the crystallization time. Consequently, copolymer (PP-R) with a POE copolymer by using a
the time required for processing was also greatly twin-screw extruder to fabricate super-toughened PP-R/
reduced. POLYM. COMPOS., 00:000–000, 2014. V C 2014 Soci-

ety of Plastics Engineers

POE blends. These blends can easily yield an Izod impact
strength of 500 J/m with the addition of only 10 wt% of
POE, whereas neat PP-R yielded an impact strength of
INTRODUCTION 180 J/m. Xu et al. [18, 19] fabricated PP/POE (80/20)
blends in a rubber mixer. A well-established droplet/
Polypropylene (PP) is one of the most widely used gen- matrix morphology formed during the initial mixing, and
eral plastics and has been employed in the construction, during the dispersed phase (POE), the domain deformed
automotive, cable insulation, and household goods indus- from a spherical droplet into elliptical droplet, even
tries. In addition to good insulating properties, PP resin has exhibiting a fibril or sheet morphology as the rotor speed
suitable properties for processing, stress crack resistance, increased.
and chemical resistance [1–3]. However, the poor impact Alternatively, nano-sized inorganic fillers can also
toughness at room temperature or low temperatures effectively toughen PP. Chan and coworkers [20–22] used
restricts industrial applications of PP. Several studies have the surface-modified calcium carbonate nanoparticles (70
been conducted in past decades to improve the impact nm) to toughen isotactic polypropylene (iPP) and deter-
resistance of PP. Blending PP with elastomers such as eth- mined that the notched Izod impact strength of the PP/
ylene–propylene copolymers [4–7] and ethylene–propyl- CaCO3 nanocomposites containing 20 wt% of CaCO3
ene–diene–monomers (EPDMs) [8–12] can effectively nanoparticles was approximately 370 J/m, whereas the
impact strength of unfilled PP was 50 J/m. As expected,
in PP/CaCO3 nanocomposites, the nanoparticles exhibited
Correspondence to: M.C. Kuo; e-mail: muchen@mail.ksu.edu.tw
DOI 10.1002/pc.22914
good nucleating effects, which increased the crystalliza-
Published online in Wiley Online Library (wileyonlinelibrary.com). tion temperature and the average lamellar thickness. In
C 2014 Society of Plastics Engineers
V addition, Chan and coworkers [22] suggested that

POLYMER COMPOSITES—2014
 TABLE 1. Recipes for the preparation of PP/elastomer/talc composites (phr).

Sample PP Talc P1250 Talc P3000 Microtalc Engage 8150 Engage 8137 Engage 8407

Neat PP 100 – – – – – –
PP/P1250 100 20 – – – – –
PP/P3000 100 – 20 – – – –
PP/MT 100 – – 20 – – –
PP/E8150 100 – – – 10
PP/E8137 100 – – – – 10
PP/E8407 100 – – – – – 10
PP/MT/E8150 100 – – 25 15 – –
PP/MT/E8137 100 – – 25 – 15 –
PP/MT/E8407 100 – – 25 – – 15

intensive ligament stretching after the nanoparticles were EXPERIMENTAL

debonded was responsible for the substantial increase in
the impact toughness of annealed PP/CaCO3 nanocompo-
Materials
sites. Other inorganic fillers, such as organoclay [23],
multiwall carbon nanotubes, carbon black [24], barium PP (grade K3029) obtained from local manufacturer in
sulfate (BaSO4) [25], and magnesium hydroxide the Formosa Chemical & Fibre Corporation and was used
(Mg(OH)2) [26], were used to fill PP and impart the func- as a matrix material for the preparation of the composites.
tional performances to the resulting PP composites. The PP was in the form of impact copolymer pellets with
PP/elastomer/inorganic-filler ternary composites can MFI of 32 g/10 min. The commercial grades of POE elas-
increase the toughness of PP and possess outstanding tomers Engage 8150 (MFI, 0.5 g/10 min), Engage 8137
mechanical properties. Premphet-Sirisinha and Preecha- (MFI, 15 g/10 min), and Engage 8407 (MFI, 30 g/10
chon [27] used calcium carbonate (CaCO3), which had an min) were purchased from DOW Chemical (USA). The
average particle size of 5.3 mm, and a maleic anhydride different particle sizes of talc P1250 (25 mm), talc P3000
(MA)-grafted ethylene–octene elastomer (EOR-MA) to (20 mm), and MT (20 mm) were purchased from Jatery
toughen PP. PP/EOR/CaCO3 (60/20/20) composites with Chemical, Taiwan.
varying MA contents (0.5–1.5 wt%) exhibited a Young’s
modulus ranging from 1.18 to 1.22 GPa, and that of neat
Sample Preparation
PP was 1.69 GPa. However, the failure energies of the
PP/EOR/CaCO3 (60/20/20) composites were as high as The PP/POE/MT composites (Table 1) were extruded
107–167 J/m, and that of neat PP was 31.3 J/m. Chen at temperatures ranging from 170 to 190 C by a twin
et al. [26] fabricated PP/POE/magnesium hydroxyl ternary screw (Werner and Pflederer, Model-ZSK 26 MEGA
composites and found that the resulting composites, compounder) using a screw speed of 500 rpm to form the
which had a POE content of 15–30 phr, exhibited a duc- PP composite pellets. The test specimens for mechanical
tile region during impact strength testing. properties and heat deflection temperature were prepared
Talc particles are inorganic and inexpensive fillers by injection molding.
used as polymer additives for reinforcement. In this
study, talc particles were employed as alternative fillers Measurements of Mechanical Properties and Heat
to toughen PP polymer. PP/POE/micro-talc (MT) com- Deflection Temperature
posites were designed for automobile bumper applica-
tion to improve the flexural toughness and heat Tensile strength and elongation at break were measured
deflection temperature. For the simplicity of processing, by a Universal Tensile Tester with a tension velocity of 25
chemical modifications or grafts were not applied to the mm/min in compliance with the specifications of ASTM
components of PP/POE/MT composites, which are dif- D638. The three-point flexure tests were performed using a
ferent from those of PP/CaCO3 [20–22] and PP/EOR/ Universal Tensile Tester at a crosshead speed of 2 mm/min
CaCO3 [27] composites. POE copolymers with varying according to ASTM D 790. Notched Izod impact tests were
melt flow index (MFI) values were selected to toughen carried out at ambient conditions according to the ASTM
the PP polymer, and talc powders with an average parti- D256. The heat deflection temperature (HDT) was deter-
cle size of 20–25 mm were used to improve the mechan- mined according to the ASTM D 648.
ical properties and heat deflection temperature of PP/
POE blends. In addition, the thermomechanical proper-
Dynamic Mechanical Property Analysis
ties, morphologies, and crystallization behaviors were
identified to evaluate the performances of PP blends and Dynamic mechanical data were obtained using a dynamic
composites. mechanical analysis (DMA) instrument (TA Q800) with the

2 POLYMER COMPOSITES—2014 DOI 10.1002/pc

 TABLE 2. The mechanical properties of the neat PP, PP/talc composites, PP/POE blends, and PP/POE/MT composites.

Sample Tensile strength (MPa) Elongation at break (%) Flexural strength (MPa) Flexural modulus (MPa) Notched Izod impact (kJ/m2)

Neat PP 21.6 363.1 26.6 803 36.3

PP/P1250 20.6 143.0 34.3 1,674 9.9
PP/P3000 21.9 120.7 36.9 1,833 9.1
PP/MT 23.0 84.6 37.3 1,944 10.2
PP/E8150 18.0 693.1 21.9 775.5 63.5
PP/E8137 18.7 630.3 25.5 791.6 59.9
PP/E8407 18.9 695.9 25.5 791.3 59.7
PP/E8150/MT 18.6 265.7 27.9 1,435.2 56.1
PP/E8137/MT 19.3 244.7 28.9 1,493.5 57.7
PP/E8407/MT 19.5 257.7 29.2 1,543.3 59.8

following parameters: frequency, 1 Hz; scan rate, 5 C/min, PP composites, including PP/talc, PP/POE blends, and
and temperature range, 2100 to 50 C. PP/POE/MT composites. The studied mechanical proper-
ties were tensile and flexural properties as well as the
notched Izod impact strength. Recipes for the PP compo-
Morphological Analysis sites are summarized in Table 1. Table 2 and Fig. 1 show
Morphology was evaluated using a JEOL JSM6360 the mechanical properties and heat deflection tempera-
Scanning Electron Microscope (SEM). The sample was tures of the resulting PP composites, respectively. As
fractured under cryogenic conditions using liquid nitrogen stated in EXPERIMENTAL section, the particle sizes of
and immersed in heptane to dissolve elastomer at ambient talc P1250, talc P3000, and MT were 25, 20, and <20
temperature for 24 h and dried to remove the solvent. mm, respectively. The inclusion of MT slightly increased
Before observation, the gold was sputtered onto the sam- the tensile strength, but also substantially reduced the
ple surface and an SEM was used to examine the sample. elongation at break (eb) of the PP/talc composites. The
values of eb decreased substantially from 363.1% for neat
PP to 84.6% for PP/MT composites. Furthermore, the
Petrographic Microscope Observations notched Izod impact strength of the PP/talc composites
A Zeiss Axioskop 40A petrographic microscope was decreased substantially compared with that of neat PP.
used to observe the spherulite morphologies of PP/ However, the flexural properties and heat deflection tem-
Engage/talc composites. A thin piece of sample was sand- peratures showed considerable improvement. The
wiched between two glass cover slips and placed on a increases in the flexural modulus and HDT of the PP/MT
digital hot-stage under nitrogen atmosphere. The hot-stage composite were 142% and 27.2 C respectively, compared
was rapidly heated to 200 C at 20 C/min and held for with those of neat PP. Excluding the elongation at break
5 min to erase the thermal history of specimens. Then, and impact strength, relatively finer talc particles led to
the PP/elastomer/MT composite melt was quenched to the
ambient temperature to observe spherulite morphology.

Differential Scanning Calorimetry Measurement

A TA differential scanning calorimeter (TA Q2000)
was applied to investigate the isothermal crystallization
behaviors of PP/POE/MT composites. The sample was
heated up to 200 C at a rate of 10 C/min under nitrogen
atmosphere. At 200 C, this sample was held for 5 min to
remove the previous thermal history, and then it was
quenched to the predetermined temperatures (142, 146,
and 150 C) to undergo isothermal crystallization process.

RESULTS AND DISCUSSION

Mechanical Properties FIG. 1. The heat deflection temperatures (HDT) of the neat PP,
PP/talc composites, PP/POE blends, and PP/POE/MT composites.
In this subsection, we focus on the mechanical proper- [Color figure can be viewed in the online issue, which is available at
ties and heat deflection temperatures of binary and ternary wileyonlinelibrary.com.]

DOI 10.1002/pc POLYMER COMPOSITES—2014 3

greater improvements in tensile strength, flexural proper-
ties, and HDT.
Regarding the effect that POE elastomers on the
mechanical properties of PP polymer, Engage 8150 (MFI,
0.5 g/10 min), Engage 8137 (MFI, 15 g/10 min), and
Engage 8407 (MFI, 30 g/10 min) can significantly and
greatly increase the elongation at break and impact
strength of PP/POE blends. The eb values for the blends
were as high as 630–695%, with the increases ranging
from 74 to 91% compared with that of neat PP. This sug-
gests that POE copolymers can increase the PP matrix
ductility. In addition, POE elastomers improved the Izod
impact strength of the PP matrix. In this study, the Izod
impact strength of neat PP was 36.3 kJ/m2, and that of
the PP/POE blends was 59.7–63.5 kJ/m2, which is an
increase of 64–75%. The MFI value exhibited less effect
on the impact strength of the PP/POE blends. Liang [2]
used a POE (Engage 8180, MFI, 10 g/10 min) to toughen
PP (MFI, 10 g/10 min). The PP/POE blend improved the
Izod impact strength from 1.9 kJ/m2 for neat PP to 3.1
kJ/m2 for the PP/POE blend at 10 phr of Engage 8180,
which is an increase of 63%. Bai et al. [28] prepared PP/
POE blends and found that the MFI values of PP and
POE were 2.5 and 11.0 g/10 min, respectively. Further-
more, POE copolymer increased the Izod impact strength
from 4.5 kJ/m2 for neat PP to 9.0 kJ/m2 for the PP/POE
(90/10) blend. Yang et al. [17] proposed that a PP/POE
(90/10) blend, which exhibited MFI values for PP and
POE (Engage 8210) of 10.0 g/10 min, increased the Izod
impact strength from 2.5 kJ/m2 for neat PP to 4.7 kJ/m2
for the PP/POE blend, which is an increase of 88%. In FIG. 2. (a) Storage modulus and (b) Tan d of PP/elastomer/talc compo-
addition to increasing the ductility of PP/POE blends, sites. [Color figure can be viewed in the online issue, which is available
blending PP with POE elastomers reduces the tensile at wileyonlinelibrary.com.]
strength, flexural properties, and HDT compared with
those of neat PP.
Thermomechanical Properties
As stated previously, the inclusion of talc particles
improved the flexural properties and HDT of PP/talc com- To investigate the effects that talc fillers and POE
posites, but deteriorated the elongation at break and impact elastomers have the dynamic mechanical properties of the
strength. In addition, except for the elongation at break, the resulting PP composites, a DMA instrument (TA Q800)
MT-filled PP composite (PP/MT) exhibited superior per- was employed to identify the thermomechanical proper-
formances in tensile strength, flexural properties, impact ties, including the storage modulus and Tan d (damping
strength, and HDT compared with the PP/P1250 and PP/ factor) of the PP composites as shown in Fig. 2. The
P3000 composites. Blending PP with POE elastomers inclusion of MT particles increased the storage modulus
improved the ductility and impact strength but reduced the of PP/talc composites compared with that of neat PP, and
tensile strength, flexural properties, and HDT. Accordingly, finer talc particles exhibited a higher storage modulus
a compromise may exist in which the optimum combina- value. The talc particles increased the storage modulus
tion of PP, MT particles, and POE copolymers may from 1,233 MPa for neat PP to 2,274 MPa for MT-filled
improve the flexural properties, impact strength, and HDT PP composites at 25 C, which is an increase of 84.4%. In
of PP/POE/MT composites. Based on this strategy, we fab- contrast, the inclusion of POE elastomers reduced the
ricated PP/POE/MT composites by using Engage 8150, storage modulus of PP/POE blends by approximately 903
Engage 8137, and Engage 8407 as the POE copolymers, MPa for all PP/POE blends. As expected, the inclusion of
and the MT and POE contents in the composites were 25 MT in the PP/POE blend increased the storage modulus
and 15 phr, respectively. As summarized in Table 2, the from 903 MPa to as high as 1,781 MPa. The trends of
PP/POE/MT composites exhibited increased flexural prop- thermomechanical measurements are consistent with the
erties, impact strength, and HDT. The increases in impact mechanical properties discussed previously.
strength and HDT were 55–65% and 13–19.2 C, respec- As reported, fillers with a 44-mm nominal diameter in
tively, compared with those of neat PP. PVAc increased the peak value of the Tan d spectrum [29, 30].

4 POLYMER COMPOSITES—2014 DOI 10.1002/pc

 FIG. 3. Morphologies of the (a) neat PP, (b) PP etched by heptane, (c) PP/POE blend, (d) PP/MT compos-
ite, and (e) PP/POE/MT composite. The POE copolymer in (c) and (d) is Engage 8407. Except for (a), all
the fractured surfaces were etched by heptane before SEM observations. [Color figure can be viewed in the
online issue, which is available at wileyonlinelibrary.com.]

However, nanofillers simultaneously increased the bulk modu- damping factor (Tan d) as shown in Fig. 2b of the resulting PP/
lus and reduced the damping factor (Tan d) of the resulting MT composite. This finding is consistent with those of PVAc
polymer nanocomposites [29–32]. The inclusion of nano-silica composites. Notably, the storage modulus of PP/POE/MT was
in PLA increased both Young’s modulus and storage modulus, as high as 1,781 MPa, and its Tan d value considerably
and simultaneously reduced the damping factor [33]. In this exceeded that of neat PP, indicating that the inclusion of a
study, MT particles not only increased the storage modulus POE elastomer substantially improves the damping properties
(Fig. 2a) of the PP polymer but also slightly improved the of neat PP.

DOI 10.1002/pc POLYMER COMPOSITES—2014 5

 FIG. 4. Illustrative models for the fractured surfaces of the (a) PP/POE blend and (b) PP/POE/MT composite.

Morphology Observation differential scanning calorimetry (DSC) at the predeter-

mined temperatures of 142, 146, and 150 C. Figure 5
To investigate the distributions of POE elastomer and
shows the melt-crystallization DSC traces. As shown in
talc particles, SEM was adopted to evaluate the surface
Fig. 5, the crystallization enthalpies (DHc) and peak crys-
morphologies of the neat PP and PP/POE blends, as well as
tallization times (sp) of the neat PP and its composites
the PP/POE/MT composite. Before observing the morphol-
were determined. In addition, the absolute crystallinities
ogy, fractured samples were immersed in heptane to dis-
(Xc) of the neat PP and its composites can be estimated
solve the elastomer. Figure 3 shows SEM images of the
by using the heat of fusion of an infinitely thick PP crys-
neat PP and PP/POE blends, and the PP/POE/MT compos-
tal, DHfo [32, 36]:
ite. Figure 3a shows neat PP that was not etched with hep-
tane and Fig. 3b shows neat PP that was etched with DHc
heptane. The voids shown in Fig. 3b resulted from the Xc 5 3100; (1)
DHfo Wpolymer
copolymer in neat PP. As-purchased PP contains this copol-
ymer, which may cause the PP polymer to be more ductile where DHfo is approximately 209.2 J/g [37], and
than the regular PP polymer is. Voids in the PP matrix were Wpolymer is the weight fraction of the polymer matrix.
considerably larger than those in neat PP when POE copoly- These crystallization parameters, including the peak
mers were incorporated as shown in Fig. 3(c). The distribu- crystallization time and absolute crystallinity, are listed
tion of the POE copolymer in neat PP was extremely in Table 3.
homogeneous. Saroop and Mathur [35] used a butadiene The inclusion of talc particles (including P1250,
styrene block copolymer (SBS) to toughen iPP and found P3000, and MT) increased the crystallinities of the PP/
that SBS droplets dissolve, leaving black voids in PP/SBS talc composites. Finer talc particles introduced addi-
blends [34]. The same occurrence was observed for HDPE/ tional crystallization sites for depositing PP molecules;
NBR blends. The surface morphology of the examined PP/ consequently, the crystallinities of PP/P1250, PP/P3000,
POE blends was similar to that of the PP/SBS blends. and PP/MT at 150 C were 48.0, 49.2, and 52.6%,
Regarding the morphology, incorporating MT particles sub- respectively, which are higher than that of neat PP
stantially reduced the dimensions of voids in neat PP and (46.7%). MT particles may induce heterogeneous nucle-
PP/POE blends as shown in Fig. 3d and e. Reduction of the ation during isothermal crystallization and considerably
void dimension substantially increased the microcrack reduce the sp values and crystallinities of PP/talc com-
length when the PP blends and composites were subjected posites compared with that of neat PP. In addition, finer
to external force as shown in Fig. 4. Accordingly, the tough- talc particles provide additional possibilities for the PP/
ness, ductility, and even bulk modulus of PP/POE/MT com- talc composites to undergo heterogeneous nucleation.
posites can be greatly improved. The findings indicated in As a result, the sp values of PP/P3000 and PP/MT com-
morphological observations of PP/POE blends and PP/POE/ posites declined compared with that of PP/P1250. Con-
MT composites are consistent with their mechanical versely, blending PP with POE copolymers reduced the
properties. crystallinity of the PP matrix because relatively fewer
crystallization sites were available. As the event
occurred in PP/talc composites, the inclusion of MT
Isothermal Crystallization Behavior
particles in PP/POE blends increased the crystallinity of
The isothermal crystallization of the neat PP, PP/POE the PP matrix and reduced the crystallization times of
blends, and PP/POE/MT composites was conducted using the blends. Thus, MT particles may serve the same

6 POLYMER COMPOSITES—2014 DOI 10.1002/pc

 both the crystallization sites and the crystallinities, they
also decreased the spherulite dimension of the PP/talc
composites.
The crystallization behavior of the PP/talc and PP/
POE/MT composites may reflect the mechanical proper-
ties of PP composites. In this study, the inclusion of talc
particles increased the tensile strength and flexural prop-
erties of PP/talc composites at the expense of reducing
the elongation at break and notched impact strength.
However, blending PP with POE elastomers yielded
opposite effects. Increases in the tensile and flexural
properties may result primarily from the stiffness of the
talc particles introduced, but increases in the crystallin-
ity of PP/talc composites can contribute to improving
the tensile and flexural properties. As summarized in
Table 3, the tertiary composites of PP/POE/MT effec-
tively and practically increased the crystallization rates
and crystallinities of the resulting composites. They also
exhibited excellent performances regarding mechanical
properties and HDT, which indicates that PP composites
with excellent mechanical properties and high impact
strength can be fabricated rapidly by including MT
particles.

TABLE 3. The absolute crystalinities (Xc) and peak crystallization

times (sp) of the neat PP, PP/talc composites, PP/POE blends, and PP/
POE/MT composites isothermally crystallized at the predetermined
temperatures.

Sample Crystallization temperature ( C) Xc (%) sp (min)

Neat PP 150 46.7 80.0

146 44.6 30.2
142 43.2 12.6
PP/P1250 150 48.0 60.4
146 46.1 23.7
142 44.8 10.0
PP/P3000 150 49.2 34.2
146 47.9 13.2
142 46.5 5.9
PP/MT 150 52.6 33.4
146 48.9 13.2
142 46.8 5.8
PP/E8150 150 42.8 77.5
146 41.3 28.8
142 38.2 11.8
FIG. 5. DSC traces of the (a) PP/talc composites, (b) PP/POE blends, PP/E8137 150 44.2 78.7
and (c) PP/POE/MT composites isothermal crystallization at 146 C. 146 42.7 29.7
[Color figure can be viewed in the online issue, which is available at 142 39.1 12.4
wileyonlinelibrary.com.] PP/E8407 150 39.6 82.2
146 38.7 30.6
142 31.4 12.9
function as PP/talc composites do, namely, heterogene- PP/E8150/MT 150 45.9 37.4
146 45.2 14.7
ous nucleation. Morphologically, the dimension of PP
142 44.0 6.2
spherulites declined continuously from approximately PP/E8137/MT 150 46.7 36.3
250 mm for neat PP to 150 mm for the PP/E8407/MT 146 45.6 14.7
composite as shown in Fig. 6. This suggests that MT 142 45.0 6.0
increased the crystallization sites and reduced the PP/E8407/MT 150 45.3 38.8
146 42.5 14.7
spherulite dimension of the PP/E8407/MT composite
142 41.7 6.2
during crystallization. Although talc particles increased

DOI 10.1002/pc POLYMER COMPOSITES—2014 7

 FIG. 6. The spherulite dimensions of neat PP and its composites at 146 C for 4 min. The spherulite dimen-
sions for the (a) neat PP, (b) PP/P1250, (c) PP/P3000, (d) PP/MT, and (e) PP/E8407/MT composites are
approximately 250, 200, 230, 190, and 150 mm, respectively. [Color figure can be viewed in the online issue,
which is available at wileyonlinelibrary.com.]

CONCLUSIONS considerably reduced the crystallization time during proc-

essing. In addition to simple and rapid processing, PP/
The inclusion of talc particles in the PP matrix
POE/MT composites exhibited excellent flexural proper-
improved the tensile strength, flexural properties, and
ties, notched impact strength, and HDT compared with
heat deflection temperature of the resulting PP compo-
neat PP and PP/POE blends.
sites, but reduced the elongation at break and notched
impact strength. As expected, adding POE elastomers to
the PP matrix yielded the opposite effect to that of PP/ REFERENCES
talc composites. However, PP/POE/MT composites were
successfully fabricated. The MT particles in ternary 1. J.Z. Liang, J. Appl. Polym. Sci., 83, 1547 (2002).
composites induced heterogeneous nucleation and 2. J.Z. Liang, J. Polym. Environ., 20, 872 (2012).

8 POLYMER COMPOSITES—2014 DOI 10.1002/pc

 3. W. Tang, J. Tang, H. Yuan, and R. Jin, J. Appl. Polym. 21. C.M. Chan, J. Wu, J.X. Li, and Y.K. Cheung, Polymer, 43,
Sci., 122, 461 (2011). 2981 (2002).
4. W.Y. Chiu and S.J. Fang, J. Appl. Polym. Sci., 30, 1473 22. Y. Lin, H. Chen, C.M. Chan, and J. Wu, Macromolecules,
(1985). 41, 9204 (2008).
5. H.P. Blom, J.W. Teh, and A. Rudin, J. Appl. Polym. Sci., 23. A. Chafidz, I. Ali, M.E. Ali Mohsin, R. Elleithy, and S. Al-
58, 995 (1995). Zahrani, J. Polym. Res., 19, 9906 (2012).
6. G.M. Kim, G.H. Michler, M. Gahleitner, and J. Fiebig, 24. S. Hom, A.R. Bhattacharyya, R.A. Khare, A.R. Kulkarni,
J. Appl. Polym. Sci., 60, 1391 (1996). M. Saroop, and A. Biswas, Polym. Eng. Sci., 49, 1502
7. I. Kotter, W. Grellman, T. Koch, and S. Seidler, J. Appl. (2009).
Polym. Sci., 100, 3364 (2006).
25. Z. Li, S. Guo, W. Song, and B. Hou, J. Mater. Sci., 38,
8. V. Choudhary, H.S. Varma, and I.K. Varma, Polymer, 32, 1793 (2003).
2534 (1991).
26. X. Chen, J. Yu, Z. Luo, S. Guo, M. He, and Z. Zhou,
9. A. van der Wal, R. Nijhof, and R.J. Gaymans, Polymer, 40,
Polym. Adv. Technol., 22, 657 (2011).
6031 (1999).
10. A. van der Wal, R. Nijhof, and R.J. Gaymans, Polymer, 40, 27. K. Premphet-Sirisinha and I. Preechachon, J. Appl. Polym.
6045 (1999). Sci., 89, 3557 (2003).
11. W. Jiang, S.C. Tjong, and R.K.Y. Li, Polymer, 41, 3479 28. H. Bai, Y. Wang, B. Song, and L. Han, J. Appl. Polym.
(2000). Sci., 108, 3270 (2008).
12. W. Jiang, D.H. Yu, L.J. An, and B.Z. Jiang, J. Polym. Sci. 29. G. Tsagaropoulos and A. Eisenberg, Macromolecules, 28,
B: Polym. Phys., 42, 1433 (2004). 396 (1995).
13. T. McNally, P. McShane, G.M. Nally, W.R. Murphy, M. 30. G. Tsagaropoulos and A. Eisenberg, Macromolecules, 28,
Cook, and A. Miller, Polymer, 43, 3785 (2002). 6067 (1995).
14. C.H. Hong, Y.B. Lee, J.W. Bae, J.Y. Jho, B.U. Nam, D.H. 31. V. Arrighi, I.J. McEwen, H. Qian, and M.B. Serrano Prieto,
Chang, S.H. Yoon, and K.J. Lee, J. Appl. Polym. Sci., 97, Polymer, 44, 6259 (2003).
2311 (2005).
32. S.S. Ray, K. Yamada, M. Okamoto, and K. Ueda, Polymer,
15. J.W. Lim, A. Hassan, A.R. Rahmat, and M.U. Wahit, 44, 857 (2003).
J. Appl. Polym. Sci., 99, 3441 (2006).
33. J.H. Wu, M.S. Yen, M.C. Kuo, and B.H. Chen, Mater.
16. A.L.N. da Silva, M.I.B. Tavares, D.P. Politano, F.M.B.
Chem. Phys., 142, 726 (2013).
Coutinho, and M.C.G. Rocha, J. Appl. Polym. Sci., 66, 2005
(1997). 34. M. Saroop and G.N. Mathur, J. Appl. Polym. Sci., 65, 2691
(1997).
17. J. Yang, Y. Zhang, and Y.X. Zhang, Polymer, 44, 5027
(2003). 35. J. George, K.T. Varughese, and S. Thomas, Polymer, 41,
18. X. Xu, X. Yan, T. Zhu, C. Zhang, and J. Sheng, Polym. 1507 (2000).
Bull., 58, 465 (2007). 36. J.H. Wu, M.S. Yen, C.W. Chen, M.C. Kuo, F.K. Tsai, J.S.
19. X. Xu, T. Zhu, L. Zhu, N. Song, and J. Sheng, Polym. Int., Kuo, L.H. Yang, and J.C. Huang, J. Appl. Polym. Sci., 125,
58, 465 (2007). 494 (2012).
20. Y. Lin, H. Chen, C.M. Chan, and J. Wu, Polymer, 51, 3277 37. R.A. Phillips, M.D. Wolkowicz, and E.P. Moore, Polypro-
(2010). pylene Handbook, Hanser, Munich (1996).

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