Which of the following polymers is synthesized using a free radical polymerization technique?

Chain - growth polymer is produced by chain-reaction polymerization in which an initiator (a free radical) adds to a carbon-carbon double bond to give a reactive intermediate. The polymer is built as more monomers add successively to the reactive end of the growing chain. Teflon, produced from tetrafluoroethylene, is an example of chain-growth polymer.

Terylene, melamine and nylon 6, 6 are the examples of step-growth polymers.