Transport of substituted benzenes through nitrile rubber/natural rubber blend membranes

Diffusion and permeation properties of substituted benzenes (aromatics) through a new variety of membranes from blends of nitrile rubber and natural rubber (NR) have been investigated in the temperature interval of 28–70 °C to characterise the physical and chemical properties of the polymer blend. These blend membranes find application in the dairy industry, where good mechanical properties and swelling resistance are required. The effects of blend ratio and penetrant size on the transport properties were studied. In the blends, the equilibrium solvent uptake decreases with an increase in concentration of nitrile rubber. The relationship between the transport behaviour and the morphology of the system was examined. The mechanism of diffusion shows an anomalous trend. The sorption data have been used to estimate the activation energies for diffusion and permeation. The van’t Hoff relationship was used to determine the thermodynamic parameters. The affine and phantom models for chemical cross-links were used to predict the nature of cross-links. The experimental diffusion data were compared with various theoretical predictions.