how is addition a chain growth polymer and condensation a step growth polymer

Dear Student,

Addition polymerization or chain growth polymerization occurs by the following three mechanisms:

1. Free radical polymerization

2. Cationic polymerization

3. Anionic polymerization.

Reaction mechanism in free radical polymerization is as follow:

Chain terminating step:

(i) By combination of free radicals

(ii) By disproportionation of free radicals

Hope it helps!