Ethanol purification from methanol via pervaporation using polybеnzoхazinonеimidе membrane☆

Abstract

Polybenzoxazinoneimide membrane was prepared in three steps: a dichlorodianhydride (obtained by the reaction of trimellitic anhydride with 4,4′-oxydianiline) was treated with methylene-bis(anthranilic acid). The resulting polyamic acid was dissolved in N-methylpyrrolidone, the solution was cast as a thin film, the solvent was evaporated and the membrane was heated under controlled conditions to convert polyamic acid into polybenzoxazinoneimide. Density, free volume parameters, sorption parameters for methanol and ethanol of the membrane were determined. The membrane was used for the pervaporation of methanol/ethanol mixtures containing 5–20wt.%methanol which aremixturesmodeling bioalcohol. Themembrane was preferentially permeated by methanol with high separation factors.