Molecular transport characteristics of poly (ethylene‐co‐vinyl acetate) membranes in the presence of normal alkanes

Solvent transport into poly (ethylene‐co‐vinyl acetate) membranes exposed to n‐alkanes has been studied in the temperature interval of 30–60°C. Pure and cross‐linked membranes were prepared. Membranes with different loading of cross‐linking agent were also prepared. It was found that for all liquids, the equilibrium penetrant uptake was influenced by the introduction of cross links. The mechanism of transport has been found to deviate from the regular Fickian behaviour. Transport parameters such as diffusion coefficient, sorption constant and permeability coefficient have been calculated. The influence of temperature on transport was analysed. Transport parameters and activation parameters for the process of diffusion have been calculated. The transport coefficients and the activation parameters showed a dependence on cross‐link density. The Van't Hoff's relationship was used to compute the entropy change. The values of polymer–solvent interaction parameters have been used to calculate the molar mass between cross links of the network polymer. The phantom and affine models were used to analyse the deformation of the networks during swelling. A correlation between theoretical and experimental results was also done. Copyright © 2007 John Wiley & Sons, Ltd.