What are Copolymer and Homopolymer?

What are Copolymer and Homopolymer?

Homopolymer

A homopolymer is the polymer which is made by linking only one type of small molecule, or monomer together.

Examples: Polyvinyl chloride

Copolymer

When two different types of monomers unite together to polymerize in the same polymer chain, that produces a copolymer.

Example: Acrylonitrile butadiene styrene (ABS), Nitrile rubber

There are mainly four types of copolymers.

• Alternating copolymer
• Random copolymer
• Block copolymer
• Graft copolymer

To understand those, let A and B are two different monomer.

Alternating copolymer: When the two monomers are arranged in an alternating fashion, the polymer is called an alternating copolymer.

-A-B-A-B-A-B-A-B-A-B-A-B-A-B-

Alternating copolymer

Random copolymer: In a random copolymer, the two monomers may follow in any order:

-A-A-B-A-B-B-A-B-A-A-B-B-B-A-

Random copolymer

Block copolymer: In a block copolymer, all of one type of monomer are grouped together, and all of the other are grouped together. A block copolymer can be thought of as two homopolymers joined together.

-A-A-A-A-A-A-A-B-B-B-B-B-B-B-

Block copolymer

Graft copolymer: When chains of a polymer made of monomer B are grafted onto a polymer chain of monomer A we have a graft copolymer.