Molecular transport of aromatic solvents in isotactic polypropylene/acrylonitrile-co-butadiene rubber blends

The sorption and diffusion of a series of aromatic hydrocarbons through blends of isotactic polypropylene/nitrile rubber have been investigated. The effects of blend ratio, vulcanizing systems and different fillers on the transport behavior were studied. In the blends, the uptake and diffusion coefficient increase with an increase in rubber concentration, and decrease with the molar volume of solvents. The diffusion data were analyzed and it has been observed that most of the systems follow a Fickian mode of transport. The effect of temperature on the transport behavior was investigated at four temperatures. The activation energy for the diffusion, and the thermodynamic parameters like entropy and enthalpy were calculated. The experimental diffusion data were correlated with various theoretical predictions. (C) 1999 Elsevier Science Ltd. All rights reserved.