LOYOLA COLLEGE (AUTONOMOUS), CHENNAI –600 034

B.Sc., DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2003

CH – 5400/CHE400/CH518 – POLYMER CHEMISTRY

07.11.2003                                                                                                          Max:100 marks

1.00 – 4.00

 

PART-A

 

Answer all the questions.                                                                                 (10×2=20 marks)

 

1. What are chain transfer agents? Give an example.
2. What are plasticizers? Give an example.
3. Define CMC.
4. Mention two disadvantages of bulk polymerization.
5. When rubber is masticated in an atmosphere of nitrogen, the degradation does not occur, but when the process is repeated in the presence of air, the degradation is very quick and significant – Explain.
6. Mention the polymer used for the following:

• Articles that can be sterilized.
• Attractive sign boards and durable lenses.

7. What are Kevlar fibres?
8. What is compounding?
9. Mention the uses of FRP.
10. How is the monomer of PAN prepared?

 

PART-B

 

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

 

11. A polymer sample consists of 5 moles of molecular weight 30,000, five moles of molecular weight 40,000 and 10 moles of molecular weight 50,000. Calculate  and .
12. Discuss the polymerization of acetonitrile in the presence of Li NH₂.
13. Explain gas phase polymerization with an example.
14. Stilbene and maleic anhydride fail to undergo self polymerization but these two react to give exclusively alternating co-polymer.
15. What are epoxy polymers? How are these prepared?
16. Give an example of photostabilizer and mention its requirement.
17. Write a note on Fibre Reinforcing Plastics.
18. Define cohesive energy and account for the high cohesive energy of polyamide.
19. What should be the criteria of conducting polymers? Give two examples of conducting polymers.

 

20. Give an example for each:

• Man made fibre
• Natural fibre
• Natural rubber
• Synthetic rubber
• Thermosetting plastic.

 

PART-C

 

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

 

21. Discuss the secondary bond forces in polymers.
22. What are stereoregular polymers? Give examples. How are these obtained?  Discuss the mechanism for the preparation stereoregular polymers.
23. Discuss emulsion polymerization.
24. Give an account of thermal degradation of polymers.
25. Write notes on

• Injection moulding
• Callendering

26. (i) Distinguish homopolymes and co-polymers.

(ii) Give the preparation and the uses of polystyrene and phenolformaldehyde resin.

 

 

 

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    LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc.

WS 22

DEGREE EXAMINATION –CHEMISTRY

FIFTH SEMESTER – APRIL 2007

CH 5400 – POLYMER CHEMISTRY

 

 

Date & Time: 30/04/2007 / 1:00 – 4:00         Dept. No.                                                     Max. : 100 Marks

 

 

PART-A                                               (10×2=20)

Answer all questions.

1. What are co-polymers? Give examples.
2. Write any two uses of the following.
3. a) Nylon     b) polyester
4. Draw the structure of isotactic polypropylene.
5. Define critical micellar concentration.
6. What is virgin polymer?
7. Give the structure of Teflon and mention its monomer and use.
8. Differentiate organic and inorganic polymers.
9. Compare bulk and solution polymerization.
10. What is nitrile polymer?
11. What are elastomers?

PART-B

Answer any eight questions.                                                                      (8X5=40)

11. Write short note on:
12. Addition polymerization
13. Condensation polymerization
14. Describe the process and reactions involved in vulcanization.
15. What are Photostabilizers? Explain their characteristics with example.
16. How are the following polymers and their monomers prepared?
17. i) Polyethylene        ii)  Buna-s
18. Explain the mechanism of alkali catalyzed polycondensation of phenol and

formaldehyde. Mention the uses of this polymer.

16. What is polymer degradation? Explain the different types of polymer degradation.
17. Write the preparation and uses of the following:
18. i) PET             ii) HDPE
19. Differentiate thermoplastics and thermosetting plastics.
20. Define cohesive energy and account for high cohesive energy of polyamide.
21. Explain the types of stereo regular polymer.
22. Write a note on ‘gas phase polymerization’.
23. What is compounding? Explain its importance.

 

 

 

 PART-C

Answer any four questions.

23. a) Explain the mechanism of free-radical polymerization with an example. (5)

b)Give an account of cationic polymerization.                                                  (5)

24. Discuss the different steps involved in emulsion polymerization. (10)
25. Write a note on fibre reinforced plastics. (10)

 

26. Write a note on:
27. Injection moulding
28. Blow moulding. (5+5)
29. What is Zeiglar-natta catalyst? Explain its advantages with mechanism. (10)
30. a) Explain the role of primary and secondary bond forces in polymers.         (6)
31. b) Give preparation, properties and uses of the following:
32. i) PVC ii) PUF                                                                   (2+2)

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

           B.Sc. DEGREE EXAMINATION – CHEMISTRY

GH 16

FIFTH SEMESTER – APRIL 2008

CH 5400 (POLYMER CHEMISTRY)

 

 

 

Date : 03-05-08                  Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

PART-A                                  

 

Answer ALL  questions.                                                                                 (10×2=20)

1. How will you differentiate oligomers from polymers?
2. Write the H-bondeed structure of polyamide and give its importance.
3. Draw the structure of isotactic polymer of polypropylene.
4. Write the photo initiation mechanism of ethylene using benzoyl peroxide.
5. What is the role of surfactants in emulsion polymerization?
6. What is pearls polymerization?
7. How is PMMA prepared?
8. Mention any two uses for each thermo and thermosetting polymers.
9. How will you increase the strength and elasticity of natural polymers?
10. Write the name of the polymer process which enables the production of following.
11.  i) Soft drink bottles

ii)Film and sheets

 

PART-B      

 

Answer any eight questions.                                                                           (8×5=40)

11. Write short notes on Mn & Mw with examples.
12. Discuss the characteristics of a monomer with three examples.
13. Discuss the geometrical isomerism of polybutadiene with structure.
14. What are living polymers? Explain with mechanism.
15. Explain the different types of polymerization.
16. What is solution polymerization? Explain its advantages.
17. How are the following polymers prepared?
18. i) Polystyrene  ii) Nylon 6,6   iii) Teflon
19. Differentiate electrometric compounds and fibre forming plastics.
20. Explain the variance of conductivity values of doped and undoped polyacetylene.
21. Discuss the advantages of die-casting.
22. Write a note on (i) antioxidats

(ii) colourants.

22. What is FRP? Explain the process of hand lay-up technique.

 

 

PART-C                                     

 

Answer any four questions.                                                                            (4×10=40)

23. a) What are secondary bond forces? Give its importance in polymers. (6)
24. b) Explain the linear and cross-linked polymer with example.                       (4)
25. What are stereo-regular polymers? Discuss the mechanism of preparation using coordination catalyst.                                                                                     (2+8)
26. Compare the bulk and gas phase polymerization techniques with example.
27. Thermal stability of polymers depends on their structure. Explain in detail with examples.
28. Explain the following polymerization process.
29. i) compression moulding                                                                                 (5)
30. ii) film casting.                                                                                                (5)
31. Give the preparation and uses of the following. (5×2=10)
32. i) Buna-S      ii) PAN      iii) Polyethylene   iv) PVC    v) Kevlar fiber.

 

 

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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?

 

 

 

 

 

 

 

 

 

 

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2011

CH 5402/5400 – POLYMER CHEMISTRY

 

 

Date : 12-04-2011              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

  Part – A (Answer all questions)                                   (10 x 2 = 20)

1. How are polymers classified on the basis of their origin?
2. What are reinforced plastics? Give an example.
3. Distinguish between organic and inorganic polymers.
4. How is polystyrene prepared?
5. What is coordination polymerization? Give an example.
6. What are the causes of chain end degradation?
7. What is ion-pair precipitation?
8. Account for the thermal stability of PTFE.
9. What are addition and condensation polymerizations?
10. Mention the significance of organosols.

 

Part – B   (Answer any EIGHT only)                              (8 x 5 =40)

1. Explain Natta’s bimetallic mechanism of polymerization.
2. Discuss the different types of polycondensation.
3. Explain copolymerization and homopolymerisation with examples.
4. What are zipping and unzipping? Give examples.
5. Explain interfacial condensation polymerization with an example.
6. Give the preparations and applications of LDPE and HDPE?
7. How are linear and cross-linked phenol-formaldehyde resins obtained?
8. Explain inter and intra molecular chain transfer.
9. How will you remove the defects in polypropylene polymer?
10. Describe polyaddition polymerization with an example.
11. Discuss the mechanism of anionic polymerization.
12. How are isotactic and syndiotactic polymers obtained?

 

 

 

Part – C   (Answer any FOUR only)                              (4 x 10 =40)

1. a) Discuss the primary and secondary bond forces present in polymer   (6)

1. b) Chain polymerization is also called vinyl polymerization – explain. (4)

1.  Why is the molecular weight of a polymer expressed as an average? Describe the   weight average molecular weight determination of a polymer.
2. a) Explain the various possible modes of addition in the propagation step of free radical polymerization.                                                                             (6)

1. b) Why are inhibitors called short stops? Mention their uses. (4)

1.  a) Explain i) Blow moulding  ii) Injection moulding                              (6)

1. b) Write a note on compounding. (4)

1. a) Discuss the role of metering and feed zones in extrusion moulding.   (5)

1. b) Writ a note on elastomeric materials and fibre forming polymers. (5)

1. Discuss the mechanisms of conduction exhibited by polyphenylene and polyacetylene polymers.

 

 

 

 

 

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2012

CH 5402/5400- POLYMER CHEMISTRY

 

 

Date : 27-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

Part – A (Answer ALL questions):                                                                              (10 x 2 = 20 Marks)          

1. Draw the structures of polyisoprene and polystyrene.
2. Define: Cohesive energy.
3. Mention the uses of polyamide and bakelite.
4. What is Zeigler-Natta catalyst? Mention its use.
5. Why anionic polymerization is also called living polymerization?
6. Mention the significance of CMC.
7. How does benzoyl peroxide initiate polymerization?
8. Mention the conditions for chain end degradation.
9. Account for the thermal stability of Teflon.
10. What are plasticizers? Give an example.

 

Part – B   (Answer any EIGHT only):                                                                            (8 x 5 =40 Marks)

1. How is the number average molecular weight of a polymer estimated?
2. Distinguish between homopolymers and copolymers with examples.
3. Discuss the importance of hydrogen bonding in polymers.
4. Explain the mechanism of preparation of PVC by cationic polymerization.
5. Write a note on step growth polymerization with an example.
6. Explain interfacial polymerization with a suitable example.
7. Mention any two uses of PTFE, Buna-N and Polyester.
8. What are known as zipping and unzipping in polymers?
9. How are (i) Nylon-6,6 and (ii) Neoprene prepared?
10. Articles made up of polypropylene can be steam sterilized – explain.
11. Explain the role of polymer additives in polymerization process.
12. Write a note on injection moulding.

 

 

 

 

Part – C   (Answer any FOUR only):                                                                          (4 x 10 =40 Marks)

1. Explain the following with suitable examples

1. a) plastics and elastomers b) natural and synthetic polymers (5+5)

1. Discuss the mechanism of the preparation of stereo-regular polypropylene using Ziegler-Natta catalyst.
2. a)  Discuss the mechanism of a free radical polymerization. (6)

1. b) Explain auto acceleration in bulk polymerization. (4)

1. Explain the acid and base catalysed mechanism of the formation of phenol-formaldehyde resin.
2. Explain the conductivity of polypyrrole, polysulphur nitriles and polyphenylene with the factor influencing their conductivity.
3. Write a note on  the following processing techniques of polymer

1. a) Calendring b) Die casting (5+5)

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2012

CH 5402/5400 – POLYMER CHEMISTRY

 

 

Date : 27-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

Part – A (Answer ALL questions)               (10 x 2 = 20 Marks)  

1. Draw the structures of polyisoprene and polystyrene.
2. Define: Cohesive energy.
3. Mention the uses of polyamide and bakelite.
4. What is Zeigler-Natta catalyst? Mention its use.
5. Why anionic polymerization is also called living polymerization?
6. Mention the significance of CMC.
7. How does benzoyl peroxide initiate polymerization?
8. Mention the conditions for chain end degradation.
9. Account for the thermal stability of Teflon.
10. What are plasticizers? Give an example.

 

Part – B   (Answer any EIGHT only)          (8 x 5 =40 Marks)

1. How is the number average molecular weight of a polymer estimated?
2. Distinguish between homopolymers and copolymers with examples.
3. Discuss the importance of hydrogen bonding in polymers.
4. Explain the mechanism of preparation of PVC by cationic polymerization.
5. Write a note on step growth polymerization with an example.
6. Explain interfacial polymerization with a suitable example.
7. Mention any two uses of PTFE, Buna-N and Polyester.
8. What are known as zipping and unzipping in polymers?
9. How are (i) Nylon-6,6 and (ii) Neoprene prepared?
10. Articles made up of polypropylene can be steam sterilized – explain.
11. Explain the role of polymer additives in polymerization process.
12. Write a note on injection moulding.

Part – C   (Answer any FOUR only)            (4 x 10 =40 Marks)

1. Explain the following with suitable examples

1. a) plastics and elastomers b) natural and synthetic polymers (5+5)

1. Discuss the mechanism of the preparation of stereo-regular polypropylene using Ziegler-Natta catalyst.
2. a)  Discuss the mechanism of a free radical polymerization. (6)

1. b) Explain auto acceleration in bulk polymerization. (4)

1. Explain the acid and base catalysed mechanism of the formation of phenol-formaldehyde resin.
2. Explain the conductivity of polypyrrole, polysulphur nitriles and polyphenylene with the factor influencing their conductivity.
3. Write a note on  the following processing techniques of polymer

1. a) Calendring b) Die casting (5+5)

 

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