Cambridge O Level Chemistry · Syllabus 5070 · Organic Chemistry
Polyester
What is Polyester?
A condensation polymer made from a dicarboxylic acid and a diol, in which the monomer units are joined by ester linkages, -CO-O-; PET is the polyester used for drinks bottles and clothing fibres.
This definition is part of the Organic Chemistry chapter in Cambridge O Level Chemistry.
Questions students ask about Polyester
What is the difference between addition polymerisation and condensation polymerisation?
Addition polymerisation joins many unsaturated monomers by opening each C=C double bond, so the polymer is the only product and nothing is released. Condensation polymerisation joins monomers that each carry two functional groups, releasing a small molecule — usually water — at every linkage formed. A polyamide forms a -CO-NH- linkage from a dicarboxylic acid and a diamine; a polyester forms a -CO-O- linkage from a dicarboxylic acid and a diol.