Sorption of Aromatic Hydrocarbons into Styrene Butadiene Rubber/Poly(ethylene-co-vinyl acetate) Blends
Benzene, toluene and xylene sorption by styrene-butadiene rubber/poly (ethylene-co-vinyl acetate) (SBR/EVA) blends in the temperature range of 26-56 °C have been investigated. The blends were vulcanised by three different systems viz. sulphur, dicumyl peroxide and a mixed system of sulphur and peroxide. The effects of various parameters such as blend composition, vulcanising systems, crosslink density, penetrant molecule size, and temperature on the sorption parameters were studied. Blends with higher EVA contents, vulcanised by the peroxide system, were found to exhibit the lowest interaction with the solvents. The mechanism of sorption deviated regularly from the normal Fickian behaviour, found for conventional elastomers, with increase in EVA content. The molecular mass between crosslinks, kinetic rate constant, transport coefficients and related thermodynamic parameters have been computed to complement the experimental observations. The experimental results have been compared with different theoretical predictions.