Transport properties of substituted benzenes through a new variety of membranes from blends of thermoplastic polyurethane (TPU) and natural rubber (NR) have been investigated at different temperatures viz., 30 degrees C, 50 degrees C and 70 degrees C to understand the effect of physical and chemical nature of the polymer blend on the transport phenomena. The effect of blend ratio, temperature and penetrant size on the sorption properties was studied. In the blends, the equilibrium solvent uptake decreases with an increase in concentration of TPU. The relationship between the transport behaviour and the morphology of the system was examined. The mechanism of diffusion is found to deviate from the normal Fickian trend. The sorption data have been used to estimate the transport coefficients and various kinetic parameters of sorption. The experimental diffusion data were compared with various theoretical predictions. (C) 2011 Elsevier B.V. All rights reserved.