The separation of hexane–acetone mixtures through HDPE/EPDM blend membranes was evaluated to investigate the polymer blend concept in developing membrane materials for pervaporation. Effects of blend ratio on the pervaporation flux at three different hexane–acetone compositions are shown in Fig. 2. From the figure, it can be observed that the transport properties of the HDPE/EPDM blends depend strongly on the HDPE/EPDM ratio in the blend. Pervaporation flux is lowest for the 100/0 HDPE/EPDM membranes and it slowly increases with an increase in the wt% of EPDM in the blend up to 50% followed by a sharp increase. This figure shows that by controlling the EPDM content in the blend a variety of fluxes can be obtained for any feed composition. In the case of a feed mixture of hexane–acetone (50/50), for example, the flux increases from 0.62 to 1.02 kg/m2 h as the EPDM content increases from 30 to 70 wt%.