Monomer types

Addition uses alkene monomers, often one monomer type. Condensation uses bifunctional monomers such as a diacid plus diol or diamine.

Atom economy

In addition polymerisation, all monomer atoms enter the polymer. Condensation polymerisation removes small molecules such as water, so the repeat unit lacks some atoms from the original functional groups.

Backbone and linkages

Addition polymers usually have a carbon-carbon backbone. Condensation polymers contain characteristic ester or amide linkages within the backbone.

Deducing process type

Look first for C=C in the monomer or -COO-/-CONH- in the polymer. Then decide whether a small molecule is formed and identify the monomer functional groups.

High-value recall and connections

Essential recall: What monomer type undergoes addition polymerisation? An alkene. What by-product is formed in addition polymerisation? None. Give one condensation-polymer linkage. Ester or amide. Practical connection: Create a comparison matrix for monomers, linkage, by-product, repeat unit and examples. Examination connection: A question asking for differences needs paired contrasts, not two separate descriptions.

Review questions and suggested answers