Engineering Chemistry S Datta

468 ENGINEERING CHEMISTRY
Polymer is:
Properties and uses
It is a glass-like plastic. It is used for making transparent sheets, rods etc. and also for
making binoculars, camera lenses, table lamp shades. It is a component of emulsion paint.
Q. 22. What is polyvinyl (Trade name: Fevicol) alcohol?
Ans. Monomer is: CH 2
=CH⎯OH (Vinyl alcohol)
Polymer is: —[CH 2
—CH(OH)—CH 2
CH(OH)—CH 2
] n
—
It is a water soluble polymer which is soft and gummy. It is used as an adhesive.
Q. 23. What do you mean by biodegradation of polymers?
Ans. Biodegradation is a process by which refuse mixes with environment by
microorganisms. This biodegradation process is completely absent in the case of high polymers.
Development of biodegradable polymer ‘biopol’ is now a challenge to scientists. Polyhydroxybutyrate
is a ‘biopol’ which degrades within a few months in soil but it is too costly to be used
very soon.
EXERCISES
1. Write short notes on (i) free radical polymerization (ii) cationic polymerization (iii) silicone resin.
2. Discuss various methods of plastic processing.
3. (a) Write short notes on
(i)addition polymerization
(ii)condensation polymerization
(iii)thermoplastic and thermosetting plastics (iv)number average and molecular weight.
(b)Write the structures, two properties and uses of:
(i) PE, (ii) PP, (iii) PVC, (iv) PTFE, (v) Nylon 66.
4. Write the structures of five addition polymers and five condensation polymers, with their respective
monomers.
5. Explain with example: (i) addition polymerization, (ii) co-polymerization, (iii) vulcanization of
rubber.
6. Write short notes on:
(i)Rayon (ii)Synthetic rubber (iii)Types of plastics.
7. (a) Discuss the effect of structure of polymers on their physical properties in detail.
(b) Give the preparation and properties of
(i) Nylon 6, (ii)Neoprene rubber (iii) SBR (iv)Silicone rubber.
8. (a) What is a heterochain polymer? Give one example.
(b)Define the term functionality of monomers. Explain its significance with suitable examples.
(c)Discuss the preparation of bakelite and PVC plastic.
(d)What are the functions of fillers and plasticizers in plastic industry?
9. Discuss briefly the application of plastic in engineering and industry.