A route to preparation of bromomethylated poly(2,6‐dimethyl‐1,4‐phenylene oxide)

Bromination of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) in halogenated aromatic hydrocarbons has been investigated in order to find optimum conditions for preparation of bromomethylated polymer when using either molecular bromine or N‐bromosuccinimide as brominating agent. It was found that bromination of the methyl group of PPO took place in chlorobenzene with dicumyl peroxide initiator at 132°C and no phenyl‐brominated product was obtained. The parallel bromination of the phenyl group and the methyl group of PPO, however, occurs at temperatures below 130°C with either molecular bromine or N‐bromosuccinimide. At temperatures above 150°C, cross‐linking of PPO accompanying the bromination starts to play the important role in PPO modification.