PERVAPORATION OF CHLORINATED HYDROCARBON-ACETONE MIXTURES THROUGH POLY(ETHYLENE-CO-VINYL ACETATE) MEMBRANES

Crosslinked and uncrosslinked ethylene-vinyl acetate copolymer membran es were prepared. The permeation characteristics in the pervaporation process were examined using carbon tetrachloride-acetone mixtures. Mod ified membranes exhibit carbon tetrachloride permselectivity, but unmo dified membranes did not display the permselectivity of crosslinked po lymer. Furthermore, membranes modified with dicumyl peroxide (DCP) sho wed a higher flux and selectivity than those of benzoyl peroxide (BP) modified ones. The effects of feed concentration, molecular size, and polarity of the permeating species on pervaporation were analyzed. The influence of crosslinking density of the membranes on pervaporation w as also analyzed. The maximum separation and flux were found to be ass ociated with an optimum amount of crosslinking agent in the membrane. A mixture of chloroform and acetone having a composition near the azeo tropic region was also separated by the pervaporation technique. (C) 1 996 John Wiley & Sons, Inc.