B.E-B.E Textile Technology 8th Sem Polymer Chemistry (Anna University Chennai-2011)
Tuesday, 06 August 2013 11:58Duraimani
B. E DEGREE EXAMINATIONS 2011
(Textile Engineering/ Textile Technology)
Polymer Chemistry
Time: 3 Hrs Max. Marks: 100
Answer all Questions
PART – A (10 × 2 = 20 Marks)
1. State the functionality of the monomers, styrene, pentaerythritol, glycerol and 1,4–butane diol.
2. State two important criteria for a polymer to form a fibre.
3. Compare the molecular weight of polymer and its distribution in free radical bulk and solution polymerisation techniques.
4. What is meant by critical miscle concentration?
5. Explain what is meant by syndiotactic and isotactic polystyrene.
6. What is meant by glass transition temperature?
7. Why polyacrylonitrile cannot be prepared by bulk polymerisation?
8. What are the materials used for the manufacture of PET by melt polycondensation?
9. What is the function of silicone oils when used as a compounding material for plastics?
10. What is the function of UV–stabilisers added to plastics?
PART B — (5 * 16 = 80 MARKS)
11. Discuss with suitable examples the classification of polymers based on the following heads.
(i) Source
(ii) Thermal properties
(iii) End applications. (16)
12. (a) (i) Discuss suspension polymerisation technique in detail. (12)
(ii) Compare the advantages and disadvantages of emulsion and suspension polymerisation techniques. (4)
Or
(b) (i) Compare addition polymerisation and condensation polymerisation with suitable examples. (8)
(ii) Compare the advantages and disadvantages of bulk and solution polymerisation techniques. (8)
13. (a) (i) Discuss the factors affecting crystallinity and crystallisability. (10)
(ii) How does crystallinity affect the properties of polymers? (6)
Or (b) (i) Explain the various phase transitions of an amorphous and a semicrystalline polymer. (8)
(ii) State with reasons which polymer has higher value in each of the following pairs of polymers.
* Polystyrene or Poly ( –methyl styrene)
* Poly (methacrylate) or Poly (butylacrylate)
* Polyethylene terephthalate or Poly (bisphenol–A carbonate)
* Nylon–6 or Nylon–11. (8)
14. (a) (i) Describe the manufacture of polyurethane foams and explain the mechanisms of foam formation when water is used as a foaming agent. (10)
(ii) How is PET manufactured and what is its uses? (6)
Or
(b) (i) Describe the manufacture of polystyrene by bulk and emulsion polymerization techniques and state its properties and uses. (8)
(ii) Explain the formation of carbon fibre with suitable reactions. (8) 15. (a) (i) State any five compounding materials with suitable examples added to plastics and explain their function. (10)
(ii) Explain the technique by which continuous polymer films are obtained. (6)
Or
(b) Write notes on any TWO of the following :
(i) Nylon 6, 6. (8)
(ii) Weight average molecular weight. (8)
(iii) Solubility parameter. (8)
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