The effect of sorbed penetrants on the aging of previously dilated glassy polymer powders. II. n-propane sorption in polystyrene

Both the rate and apparent equilibrium of propane sorption in glassy polystyrene were increased after swelling the polymer by exposure to a highly sorbing vapor. Cyclic sorption experiments revealed that the increase in rate and apparent equilibrium of sorption due to the preswelling treatment decayed only during vacuum aging. The presence of low levels of propane in the polymer during aging, however, appeared to arrest the decay in sorption capacity. These composite results, taken in conjunction with the results of previous work in our laboratory, suggest that the component of the total sorption which resides in nonequilibrium, distended interchain gaps retards the chain motions which otherwise lead to consolidation of the dilated glass.