Key ideas1 of 3
Two functional groups allow chains
Condensation polymerisation uses monomers with two functional groups so each monomer can join at both ends. In a simple polyester, one monomer is a diol with two OH groups, and another is a dicarboxylic acid with two COOH groups. Their reactions create ester links between units. Repetition produces a long chain rather than only one ester molecule made from two single-functional-group reactants.
