LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

 

DB 15

FIFTH SEMESTER – November 2008

CH 5402/CH 5400 – POLYMER CHEMISTRY

 

 

 

Date : 12-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART-A                                       

 

Answer ALL questions.                                                                                      (10×2=20 marks)           

 

1. What are natural polymers and how do they differ from synthetic ones?
2. Define inorganic polymers.
3. What are polycondensation polymers? Give only the names of the monomers used for the synthesis of polyamide .
4. Write any four characteristic features of anionic polymerization.
5. What is bulk polymerization? Mention any two drawbacks of bulk polymerization.
6. Why is the thermal stability of Teflon high?
7. How are the following serve as initiators?

(a) benzoyl peroxide           (b) azobisisobutyronitrile.

8. How is polystyrene prepared?
9. What are antioxidants? Give any two examples.
10. How does the reinforcement affect the properties of rubbers and plastics?

 

PART-B

 

Answer any EIGHT questions.                                                                                (8×5=40 marks)

 

11. Define the following with example for each (a) Oligomers     (b) Elastomers
12. Suggest ways to help make the synthetic polymers eco-friendly.
13. Distinguish addition polymerization and condensation polymerization reactions.
14. Describe the kinetics of chain polymerization by free radicals.
15. Write short notes on gas phase polymerization.
16. Explain the factors influencing the stability of polymers.
17. Write short notes on (a) ring opening polymerization (b) living polymers.
18. Mention the steps involved in the formation of bakelite and explain.
19. How are the following polymers synthesized?

(a) HDPE       (b) Neoprene

20. Explain the role of the following with example:

(a) Plasticizers  (b) Fire retardants

21. Explain the process of calendaring.
22. Discuss the stages involved in and importance of blow moulding.

 

 

PART-C                                                 

 

Answer any FOUR questions.                                                                                  (4×10=40 marks)

 

23. Discuss the importance of secondary bond forces in polymers with suitable example

for each case.

24. Write mechanism of Ziegler Natta polymerization. How is the growing chain

terminated?  Why are stereo-regular polymers obtained from it?                                       (6+2+2)

25. Explain the mechanism of emulsion polymerization.
26. Discuss the different types of polymer degradation and explain any one methods of

prevention for each type.

27. What are conducting polymers? What are their characteristics of conducting

polymers?  Explain with the conductance value for polysulphurnitriles, polyphenylene,

poly pyrrole and polyacetylene.                                                                                          (2+4+4)

28. Explain three major techniques of FRP and mention their applications?

 

 

 

 

 

 

 

 

 

 

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