1. ADDITION POLYMERS:

The repeated addition of monomers with double or triple bonds leads to the formation of addition polymers. The double or triple bonds break to form a single bond and the molecular chain is formed. Thus, Polyvinyl chloride, Polythene are addition polymers.

2. CONDENSATION POLYMERS:

The repeated condensation of 2 different bi-functional or tri-functional groups leading to the elimination of simple molecules like water, hydrogen chloride leads to the formation of condensation polymers. Thus, Terylene, Bakelite are condensation polymers.