Condensation polymers are any class of polymer formed through a condensation reaction, as opposed to addition polymers which involve the reaction of unsaturated monomers. Types of condensation polymer include polyamides and polyesters.

Nylon is a common condensation polymer. It is manufactured by reacting di-amines with carboxyl derivatives. In this example the derivative is a di-carboxylic acid, but di-acyl chlorides are also used:

The carboxylic acids and amines link to form peptide bonds, also known as amide groups. Proteins are condensation polymers made from amino acid monomers. Carbohydrates are also condensation polymers made from sugar monomers such as glucose and galactose.

Condensation Polymers, unlike Addition polymers are bio-degradable. The peptide or ester bonds between monomers can be hydrolysed by acid catalysts or bacterial enzymes breaking the polymer chain into smaller pieces.

See also: Biopolymer, Polyester, Polyamide