Synthesis, properties and gas separation performance of poly(arylene ether sulfone) containing imide pendant groups

Abstract

The precursor poly(arylene ether sulfone) containing amino-groups was synthesized by a nucleophilic polymerization route, and then modified using three commercially available anhydrides. The anhydride modified polymers had fractional free volume (FFV) values in the range of 0.128–0.162, and good mechanical, thermal and gas transport properties, which were correlated with the polymer chain structure. They showed higher glass transition temperatures in the range 207–227 °C compared with the precursor polymers due to the introduction of imide pendant groups, and better thermal stability with 5% weight loss above 512 °C. The incorporation of imide pendant groups into poly(arylene ether sulfone)s improved the gas transport performance evidently due to the higher fractional free volume. The anhydride modified polymer Br-PAES-20 possesses higher permeability and permselectivity simultaneously. The most permeable membrane PEP-PAES-60 showed permeability coefficients of 8.66 barrers to O₂, 0.64 barrers to N₂ and 13.56 barrers to CO₂, with an ideal selectivity factor of 13.53 for the O₂/N₂ pair.