EFFECTS OF AGING ON THE GAS-PERMEABILITY AND SOLUBILITY IN POLY(1-TRIMETHYLSILYL-1-PROPYNE) MEMBRANES SYNTHESIZED WITH VARIOUS CATALYSTS

The effects of aging on the gas permeability and solubility in glassy poly(1-trimethylsilyl-1-propyne) (PMSP) membranes were investigated in terms of polymer characterization and storage environment. Under the aging conditions in the presence of vacuum pump oil vapor, in which a very small amount of vacuum pump oil vapor sorbed in the PMSP membrane served as an accelerator of physical aging rather than as a filler, the aging of the gas permeability of the PMSP membranes was dependent on their thickness, the polymerization catalyst and molecular weight. On the other hand, catalyst dependence on the gas permeability was not observed during annealing. Additionally, the aging of the gas sorption in the PMSP membranes was similar to that of the gas permeability. Storage in liquid nitrogen and exposure to carbon dioxide at 40 atm also affected the gas permeability and solubility in the PMSP membranes. These phenomena could be related to a difference in the glassy state of the as-cast membranes synthesized with various catalysts.