Functional polymers and sequential copolymers by phase transfer catalysis, 3. Syntheses and characterization of aromatic poly(ether sulfone)s and poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) containing pendant vinyl groups

Abstract

AbstractA method for the syntheses of α,ω‐dibenzyl aromatic poly(ether sulfone)s (PSU) and poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) (POP) containing pendant vinyl groups is presented. The first step of the synthetic procedure involves the chloromethylation of PSU and POP to provide polymers with chloromethyl groups. POP, containing bromomethyl groups, was obtained by radical bromination of the methyl groups. Both chloromethylated and bromomethylated starting materials were transformed into their phosphonium salts, and then subjected to a phase transfer catalyzed Witting reaction to provide polymers with pendant vinyl groups. A PSU, containing pendant ethynyl groups, was prepared by bromination of the PSU, containing pendant vinyl groups, followed by a phase transfer catalyzed dehydrobromination. Differential scanning calorimetry of the thermal curing of the polymers containing pendant vinyl and ethynyl groups showed that the curing reaction is much faster for the polymers containing vinyl groups. The resulting network polymers are flexible when the starting polymer contains pendant vinyl groups, and very rigid when it contains pendant ethynyl groups.