Describe the four types of copolymers.

Explanation

I. Chain initiation step Here, an initiator is used as free radical (R) which initiate chain reaction as follows:
` H_2 C = underset(CH_3) underset(|) C - CH = CH_2 + overset(*)(R ) to RCH_2 - underset(CH_3) underset(|)C = CH- overset(* )(CH_2)`
II. Chain propagation step
` R-CH_2 - underset(CH_3) underset(| )C=CH-CH_2 -CH_2 - underset(CH_3) underset(|)C-CH=CH_2 to R-CH_2 - underset(CH_3 ) underset(| ) C-CH-CH_2 -CH_2 - underset(CH_3) underset(|)C=CH - overset(*)(CH_2) to `