Pervaporation of organic liquid-water mixtures through substituted polyacetylene membranes

Abstract

A poly [1-(trimethylsilyl)-1-propyne][poly(TMSP)] membrane proved highly permselective for ethanol in EtOH-H 2O pervaporation, where the separation factor, α H 2O EtOH, reached 17 at 10 wt.% of ethanol in the feed. This value is similar to that for poly (dimethylsiloxane), a well-known ethanol-permselective membrane. Because of membrane swelling, α H 2O EtOH value decreased and the total specific permeation rate increased with increasing ethanol content in the feed. In the pervaporation of combinations of water and various organic liquids through poly (TMSP), the α H 2O org.liq. values for acetonitrile and acetone exceeded 70 at ≈10% of organic liquid in the feed. In the EtOH-H 2O pervaporation through various substituted polyacetylene membranes, aliphatic polymers {e.g., poly [1-(n-hexyldimethylsilyl)-1-propyne] and poly (1-chloro-1-octyne)} showed more or less ethanol permselectivity, while aromatic polymers [e.g., poly (1-chloro-2-phenylacetylene) and poly (1-phenyl-1-propyne)] were rather water-permselective.