Copolymers are polymers that are composed of 2 different monomer units. Such bistructural copolymers can be divided into 5 different classes:
- Statistical copolymers: Copolymers where the distribution of the two monomer units in the chain is random (AABABBBABAABABABABBABABAB....).
- Gradient copolymers: Copolymers are in principle similar to statistical copolymers, but with a variable proportion of a monomer in the chain (AAAAAABABBAABABABABABABABABABABBBBB).
- Alternating or alternating copolymers: Copolymers with a regular arrangement of monomers along the chain (ABABABABABABABABABABABABABAB....).
- Block copolymers: copolymers in which two longer sequences or blocks of each monomer follow each other (AAAAAAAAABBBBBBBBBBBBBBBB...). Depending on the number of blocks these are also called diblock, triblock, ..., copolymers.
- Graft copolymers: Copolymers in which blocks of one monomer are grafted onto the backbone of another monomer.