Comment on:
(a)    PVC is a hard plastic but polyethylene is soft  wax-like.

(b)    Addition of sulphur to nutural rubber improves its properties.

(c)    Polypropylene is preferred ever polyethylene.

What are polyamides? How is nylon-66 synthesised? Give its uses.

Briefly describe the following terms giving one example of each:
(i) Polyolefins   
(ii) Polyamides
(iii) Polyesters    
(iv) Polydienes

Could a copolymer be formed in both addition and condensation polymerization or not? Explain with examples.

165.

What is orlon? Give its method of preparation. Give one of its uses.

Write the equations for the synthesis of:
Polymethyl methacrylate
Also give one important use of it.

Write the equations for the synthesis of:
Polyacrylonitrile
Also give one important use of it.

Write the equations for the synthesis of:
Teflon, Also give one important use of it ?

Write the equations for the synthesis of:
PVC, Also give one important use of it.

Write the equations for the synthesis of:
Glyptal.
Also give one important use of it.