Polymerization of α‐halogenated p‐xylenes with base

Abstract

AbstractVarious α‐halo‐p‐xylenes have been polymerized with base yielding p‐xylylene polymers. The reaction involves a 1,6‐dehydrohalogenation to give a xylylene which then polymerizes. α,α′‐Dichloro‐p‐xylene forms poly‐α‐chloro‐p‐xylylene and polymers containing stilbene units; α,α,α′,α′‐tetrachloro‐p‐xylene gives poly‐α,α,α′‐trichloro‐p‐xylylene; alkyl, aryl, and halogen ring‐substituted α‐chloro‐p‐xylenes give the corresponding ring‐substituted poly‐p‐xylylenes. The more halogens in the α positions (up to five), the weaker the base necessary for dehydrohalogenation. Sodium hydroxide in methanol will polymerize tetrachloro‐p‐xylene, while potassium tert‐butoxide in refluxing p‐xylene is necessary to polymerize α‐chloro‐p‐xylenes. Stilbenes are formed when α‐halo‐p‐xylenes are reacted with potassium tert‐butoxide in polar solvents such as dimethyl sulfoxide.