Anomalous penetrant transport in glassy polymers V. Cyclohexane transport in polystyrene

Transport of liquid cyclohexane through well characterized, initially glassy, crosslinked polystyrene slabs was investigated. The samples were produced by bulk polymerization of styrene and divinyl benzene using benzoyl peroxide as an initiator at 90°C for 48 h; they had initial crosslinking ratios, X, between 0.005 and 0.025 mol DVB/mol styrene, initial thickness of 0.25 mm to 1.80 mm, and the aspect ratio was maintained above 10 to achieve one-dimensional transport. The results of cyclohexane uptake as a function of time were used to elucidate the effects of degree of crosslinking and sample geometry on the mechanisms of penetrant transport. These results were interpreted in terms of relaxational and diffusional mechanisms.