Q. Discuss the classification of polymers.

                  OR

How are polymers classified? Explain with suitable examples.

Ans.

Polymers are classified on the basis of their three dimensional structure, tactility and functionally.

1.  Three dimensional structure: A polymer may consists of identical monomers of different and accordingly they are called homopolymers and copolymers respectively. Thus,

-M-M-M-M-M-M-M-M-M (Homopolymers)

-M₁-M₂-M₁-M₂ -M₁-M₂-M₁-M₂ (Copolymer)

The nonnumeric unit in a polymer may be presenting in linear, branched and cross linked structure. Example:

 -M-M-M-M-M-M-M-M-M- (linear polymer)

-M₁-M₂- -M₁-M₂- -M₁-M₂-M₁-M₂- (Linear polymer)

Tacticity: The orientation of nonnumeric units in a polymer molecule can take place in an orderly or disorderly fashion with respect to the main chain. The differences in configuration do affect their physical properties.

1.                 The head to tail configuration is called isotactic polymer:

2.                 Arrangements of functional groups are of random around the main chain. It is called atactic polymer.

3.                 Arrangement of side groups is in alternating fashion. It is called syndiotactic polymer.