Copolymers

A polymer derived from more than one species of monomer.

Note: Copolymers that are obtained by copolymerization of two monomer species
are sometimes termed bipolymers, those obtained from three monomers terpolymers,
those obtained from four monomers quaterpolymers, etc.

Alternating copolymers: A copolymer consisting of macromolecules comprising
two species of monomeric units in alternating sequence.

Note: An alternating copolymer may be considered as a homopolymer derived from
an implicit or hypothetical monomer.

Block copolymers: A portion of a macromolecule, comprising many constitutional
units, that has at least one feature which is not present in the adjacent portions.

Graft macromolecule: A macromolecule with one or more species of
block connected to the main chain as side-chains, these side-chains having constitutional
or configurational features that differ from those in the main chain.

When two or more different monomers unite together to polymerize, their result is called a copolymer and its process is called copolymerization.

Commercially relevant copolymers include acrylonitrile butadiene styrene (ABS), styrene/butadiene co-polymer (SBR), nitrile rubber, styrene-acrylonitrile, styrene-isoprene-styrene (SIS) and ethylene-vinyl acetate.

Since a copolymer consists of at least two types of constituent units (also structural units), copolymers can be classified based on how these units are arranged along the chain. These include:

Copolymers may also be described in terms of the existence of or arrangement of branches in the polymer structure. Linear copolymers consist of a single main chain whereas branched copolymers consist of a single main chain with one or more polymeric side chains.

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