Molecular transport of aliphatic hydrocarbons through styrene butadiene rubber/ethylene vinyl acetate blends

Abstract

AbstractPolymer blends based on styrene butadiene rubber and ethylene vinyl acetate (EVA) were prepared. The sorption and diffusion of four aliphatic hydrocarbons through the blends were investigated with temperatures of 26–56°C. Sulfur, dicumyl peroxide (DCP), and a mixed system consisting of sulfur and DCP (mixed) were used as crosslinking agents for the blends. Of the three systems, the peroxide vulcanized blends were found to exhibit the lowest penetrant uptake. The aliphatic liquid penetration through the matrix decreased with an increase in the EVA content in the blends, which was attributed to the semicrystalline nature of the EVA matrix. The experimental observations were correlated with the morphology of the blends. Diffusion and permeation coefficients were calculated from the sorption data. A slight deviation from the Fickian trend was observed for the mechanism of transport with an increase in the EVA content in the blends. The molecular mass between crosslinks and thermodynamic parameters of sorption were determined from swelling data. The experimental observations were compared with different theoretical models. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2884–2897, 2006