A new kind of membrane was prepared by blending styrene-butadiene rubber (SBR) and natural rubber (NR) in equal proportions. These membranes were crosslinked by four different vulcanising systems viz. conventional (CV), efficient (EV), dicumylperoxide (DCP) and a mixture consisting of sulphur and peroxide (mixed). The properties of these membranes were evaluated by pervaporation separation of chlorinated hydrocarbon and acetone mixtures. The experimental results showed that the selectivity and the fluxes of these membranes depended on the nature and distribution of crosslinks between the macromolecular chains of the membrane. The effects of feed composition and the molecular size of the permeate on the permeation flux and selectivity were investigated.