The mechanism by which polymers are produced from two or more monomeric units is known as co-polymerization. There are several units of each monomer in a copolymer.

Following are the two examples of co-polymerization:

(a) The process of producing the polymer Buna-S from 1, 3-butadiene, and styrene is an example of copolymerization.

(b) Adipic acid and hexamethylenediamine are used to make the copolymer Nylon 6, 6.