Q6/6H/11-13 Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 ECH618 - POLYMER CHEMISTRY Time : 3 hrs

Max Marks :75

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SECTION A (20x1=20) Answer ALL the questions. Choose the best answer 1. Nylon-6 is prepared from (a)Hexamethylenediamine

(b)Adipic acid

(c)ω –amino caproic acid

(d)None

2. T g /T m for symmetrical polymer is R

R

R

R

(a)1/2

(b)2/3

(c)3/2

(d)0.33

3. Polypeptide configuration is (a) α–helical

(b)β –pleated

(c)right hand helical (d) all

4 . _________ was the first synthetic polymers (a) bakelite

(b) PNC

(c)PAN

5. Parkesine was later named as _____________. (a)celluloid

(b)cellulose acetate

(c)nitro cellulose

6. Silicone elastomers are either room temperature ___________ (a) vulcanisation

(b) heat cure silicone rubber (c) both a & b

7.To express __________ as a function of the polymer transfer constant (a)branching density (b)linear density

(c)cross linked density 1

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8.Nylon 6,10 is used to manufacturing of (a) brushes

(b) textile fibre

(c) tyre cord

9. Hardening of plastics often involves cross linking. This process is called a. Curing

b. Vulcanisation

c. Compounding d. Plasticization

10. Transfer modeling method is used to prepare a. Thermoplastic material

b. Thermosetting material

c. Both a and b

d. None

Fill in the Blanks

(5x1 = 5)

11. Quartz is an example of polymer _______________ . 12. Rayon is also known as ________________. 13. PMMA is a ______________ polymer. 14. Stereoregular polypropylene is a highly __________ and can be used as fiber. 15. __________ polymer conduct electricity. Match the following 16. Resol resin

-

17. Liquid epoxy resin

(a) Dicarboxylic Acid + Diamine -

(b) Tiny hollow sphere

18. Araldite resin

-

(c) Phenol + HCHO

19. Polyamide

-

(d) Aircraft construction

20. Cenosphere

-

(e) Bisphenol A + epichlorohydrin 2

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SECTION B (10x2=20) Answer any TEN questions 21. How will you differentiate T m and T g ? R

R

R

R

22. Write short notes on tensile strength and fatigue? 23. How is the number average molecular weight related to weight average molecular weight? 24. What is the difference between thermoforming and foaming? 25. Write short notes on abrasion resistance and impact? 26. What is Viscoelstic state? 27. Explain degree of polymerisation 28. Explain Compounding 29. Differentiate Plastic,Elastomers and Fibers. 30. Write the difference between thermoforming and foaming 31. Write down the expression for M w ,M n ,M z and M v R

R

R

R

R

R

R

32. Explain poly dispersity and molecular weight with average molecular weight. SECTION C (5x7=35) Answer any FIVE questions 33. a. Explain the classification of polymers with examples. b. Correlate Tg and Tm

(4) (3)

34. a. Explain Morphology and order in crystalline polymers.

(4)

b. Differentiate Linear, Branched and network Polymers.

(3) 3

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35. a. Write down the preparation and uses of any three Polyamides. (4) b. Explain in detail about Phenolic polymers.

(3)

36. How will you use X-ray diffraction and NMR study in the polymer morphology ?

(7)

37. a. Compare the properties of LDPE and HDPE

(4)

b. What are the common additives incorporated in polymers? (3) 38. a. Mention any four trade names of epoxy resin.

(4)

b. Mention three types of epoxy resin.

(3)

39. Write short note on a. Film casting

(3)

b. Polyamides

(4) ************

4