Heteropolymers

Heteropolymers are polymers in which the repeating unit is formed from two or more chemically distinct monomers. This distinguishes them from homopolymers, which contain a single monomer type. Heteropolymers arise by copolymerization of different monomers or by assembling sequences of different units within a polymer chain.

Common architectures include random copolymers, alternating copolymers, block copolymers, and graft copolymers. In random copolymers the monomer units are distributed irregularly; alternating copolymers feature a regular sequence of two monomers; block copolymers consist of long blocks of each monomer; graft copolymers have side chains of one monomer on a backbone of another. Polymers with three or more monomer types are terpolymers or higher-order copolymers.

Natural heteropolymers include proteins, made from amino acid monomers, and nucleic acids, composed of nucleotide monomers. Polysaccharides can also be heteropolymers when built from different sugar units. Synthetic heteropolymers are widely used in plastics and materials science, including polystyrene–butadiene copolymers and various block copolymers used as thermoplastic elastomers.

These materials are prepared by copolymerization techniques such as radical polymerization, condensation polymerization, or living/controlled polymerization methods that allow control over composition and sequence. The arrangement and ratio of monomer units influence properties such as crystallinity, glass transition temperature, solubility, degradability, and mechanical performance.

Applications of heteropolymers span coatings, adhesives, elastomeric materials, hydrogels for biomedical use, drug delivery systems, and advanced materials with nanoscale phase separation. The ability to tailor monomer composition and architecture enables customization of properties for specific applications.