Addition polymer

An addition polymer is a polymer which is formed by an addition reaction, where many monomers bond together via rearrangement of bonds without the loss of any atom or molecule under specific conditions of heat, pressure, and/or the presence of a catalyst. This is in contrast to a condensation polymer which is formed by a condensation reaction where a molecule, usually water, is lost during the formation.

An addition polymer is formed by a reaction known as polyaddition or addition polymerization. This can occur in a variety of ways including free radical polymerization, cationic polymerization, anionic polymerization and coordination polymerization.

Most of the common addition polymers are formed from unsaturated monomers (usually having a double bond). This includes polyethenes, polypropylene, PVC, Teflon, Buna rubbers, polyacrylates, polystyrene, and PCTFE. Addition polymers are also formed from monomers that have a closed ring. Through coordination polymerization, even saturated monomers can form addition polymers.

When two or more types of monomer undergo addition polymerization, the polymer formed is known as an addition copolymer. Saran wrap, formed from polymerization of vinyl chloride and vinylidene chloride, is an addition copolymer.

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