MEMBRANES BASED ON POLY(STYRENE-N-PHENYLMALEIMIDE) POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) BLENDS

Blend membranes were prepared by casting chloroform solutions of mixtu res of styrene-N-phenylmaleimide copolymer containing ca. 10 mol % imi de units with poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), and their phase behavior was evaluated. At a content of 20% PPO, the membranes w ere homogeneous; those having 40 or more % PPO exhibited phase separat ion. Membranes made of the parent polymers and their blends were teste d in the pervaporation of aqueous ethanol solutions; permeabilities to oxygen, nitrogen, and carbon dioxide were also determined. The pervap oration characteristics and gas transport properties are discussed con sidering the interactions of polymer chains and the phase structure of the membranes. (C) 1995 John Wiley & Sons, Inc.