PENETRANT TRANSPORT IN CROSS-LINKED POLYSTYRENE

Swelling studies of cross-linked polystyrene were described, as performed in several penetrants including aromatic and aliphatic compounds at 50 and 70-degrees-C. Aromatic penetrants such as toluene and dibutyl phthalate caused sample cracking. For aliphatic penetrants such as heptane, decane, and dodecane, the penetrant transport rate, equilibrium penetrant uptake, and degree of penetrant overshoot were affected by several parameters such as the sample cross-linking ratio, penetrant size, and experimental temperature. The temperature dependence of the polystyrene/dodecane interaction parameter was estimated from the results of dodecane equilibrium uptake for polystyrene samples cross-linked at different levels. Dynamic swelling studies were analyzed with a simple exponential expression. The values of the diffusional exponent indicated that the transport mechanism varied with the sample cross-linking ratio, penetrant chain length, and experimental temperature of each system studied.