BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE – PILANI,
HYDERABAD CAMPUS
FIRST SEMESTER 2018-2019
COMPREHENSIVE EXAMINATION: CHEM F325 Closed Book POLYMER CHEMISTRY
Duration 3hrs PART A (1 h, 30 Marks) Date: 04.12.2018 Maximum Marks: 90M
Instructions: The examination consists of two parts. Part A consists of 15 questions (for 30 marks)
which have to be answered at the appropriate box given. Use the last two sheet’s of the main answer
book for rough work. The maximum time allowed for Part A is 60 min. Each correct answer carries 2
marks and 0.5 mark will be deducted for each wrong answer. Part B (Descriptive) is for 60 marks and
may be collected as soon as Part A is submitted. DO NOT OVERWRITE. Pencil should not be used.
Name: ID. No.:
Q. No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ans
No. of correct ans:_______ No. of wrong ans:_______ No. unanswered: _____ Total Marks: _____
1. The most convenient technique for characterizing the complete molecular weight distribution of a polymer
is (a) Light scattering (b) Viscosity (c) Gel permeation (d) Osmometry
2. The limitation of low angle light scattering technique is that
(a) Chain dimension can be obtained because obtained scattering is measured at single
angle
(b) Chain dimension cannot be obtained because obtained scattering angle is measured at single angle
(c) Chain dimension can be obtained because obtained scattering is measured at several angles
(d) Chain dimension can be obtained because concentrated solutions are used
3. Among the following which is the factor to decrease the Tg of a polymer
(a) Bulky side group (b) H-bonding (c) Crystallization (d) Plasticization
4. The relationship with Tg and molecular weight is
(a) Tg ∝ M (b) Tg ∝ M (Upto 20,000) (c) Tg ∝ 1/M (d) Tg ∝ M (Upto 10,000)
5. Which of the following is introduced in a polymer to enhance the conducting property
(a) Glass fiber (b) Mica (c) Carbon fiber (d) LDH nanoclay
6. The polymer A having Tg of 100 oC is mixed with polymer B (Tg is -100 oC) with 30 wt% of A to form a miscible
blend by inverse rule of mixing. What will be the overall Tg of the mixture
(a) -40.0 oC (b) -64.7 oC (c) – 67.4 oC (d) -38.2 oC
7. In a polystyrene polymer with Mw of 100,000, the molecular weight between two successive entanglements
is 15,000. What would be the critical molecular weight of polystyrene sample
(a) 50,000 (b) 15,000 (c) 31,200 (d) 7,500
8. Kevlar is commercial name for
(a) Glass fibers (b) Carbon fibers (c) Aramid fibers (d) Carbon fibers
9. A prepared polystyrene polymer having number average molecular Weight of 20,000. What would be the Tg
of the prepared polymer if the maximum glass transition temperature is given 100 oC and K for polystyrene
is 1.2 x 105 K
(a) 94 oC (b) 100 oC (c) 194 oC (d) 60 oC
10. One example of electrochromic organic polymer is
(a) Polybismaleimides (b) Polyisoprene (c) Polythiophene (d) Glyptal
11. For flexible polymer chains if the melting temperature is 330 K then the glass transition temperature would
be
(a) 330 to 660 K (b) 150 to 330 K (c) 165 to 220 K (d) 165 to 440 K
12. Which of the following polymer is having with the highest decomposition temperature?
(a) ABS (b) Nylon 6 (c) polyoxazole (d) Polyhydroxybutyrate
13. Which polymer is used as a marine adhesive
(a) PEEK (b) Novolac (c) Resole (d) Glyptal
14. Polyacetylene based polymer can be doped by alkali metal like Na to increase the conductivity. What kind of
doping it is called
(a) Alkali Doping (b) p-doping (c) n-doping (d) Acid doping
15. Ammonium polyphosphate is usually mixed with polyurethane polymers. What is the role of it in the
mixture
(a) Hardener (b) Reinforcement material (c) Antioxidant (d) Fire retardant
