Polyacrylonitrile (PAN) is produced through the polymerization of acrylonitrile using a radical initiator.
\[
n \, CH_2=CH-CN \xrightarrow{\text{Peroxide}} [-CH_2-CH(CN)-]_n
\]
Polyacrylonitrile is commonly used in the textile industry and as a precursor for the production of carbon fibers.