Pervaporation of acetone-chlorinated hydrocarbon mixtures through polymer blend membranes of natural rubber and epoxidized natural rubber

Transparent nonporous membranes were prepared by blending natural rubber (NR) with epoxidized NR (ENR). These blend membranes were evaluated for the selective separation of chlorinated hydrocarbons from acetone. The flux and selectivity of the membranes were determined both as a function of the blend composition and feed mixture composition. Results showed that polymer blending method could be very useful to develop new membranes with improved permselectivity. Pervaporation properties could be optimized by adjusting the blend composition. NR/ENR 70/30 and NR/ENR 30/70 composition showed a decrease in flux and selectivity, whereas the 50/50 composition showed increased flux and increased selectivity. Chlorinated hydrocarbons permeated preferentially through all the tested membranes. The feed mixture composition also strongly influenced the pervaporation characteristics of the blend membranes. Permselectivity was found to depend on the molecular size of the penetrants. (C) 1999 John Wiley & Sons, Inc.