Compatibility of PVC/EVA blends and the pervaporation of their blend membranes for benzene/cyclohexane mixtures

Binary blends and their blend membranes of poly(vinyl chloride) and low molecular weight ethylene-co-vinyl acetate copolymer with 38 wt.% VA content (PVC/EVA) have been prepared by solution blending. The compatibility of the blends was investigated by viscometry and Fourier transform infrared (FTIR). It was found that the PVC is compatible with the EVA when EVA weight fraction (WEVA) is less than 0.25 or larger than 0.45. The blend membranes with WEVA≤0.15 have good resistance to benzene/cyclohexane mixtures with benzene content up to 50 wt.% at 30 °C. Both degree of swelling and the permeation flux of these blends membranes increase greatly with increasing WEVA from 0 to 0.2.