Pervaporation through membranes made from acyl derivatives of poly(2,6‐dimethyl‐1,4‐phenylene oxide)

Several acyl derivatives of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) were obtained by Friedel—Crafts acylation, and the products were used to prepare membranes. During the pervaporation of 10% aqueous solutions of ethanol, acetone, 1‐propanol, or dioxan, membranes made from unmodified, benzoylated, or propionylated PPO (glassy polymers, T g > 200°C) were preferentially permeable to water, and their separation factors were mainly dependent on the molecular weight of the solvent. Membranes made from palmitoylated PPO (nonglassy polymer, T g = 34.9°C) were preferentially permeable to organic solvents, and their separation factors correlated with the solubility parameters of the solvents under investigation. As regards membranes made from caproylated PPO ( T g = 130.6°C), there was no unambiguous relation to molecular weights of the solvents or to their solubility parameters. © 1992 John Wiley & Sons, Inc.