Physical Aging of Membranes for Gas Separations

Research Center [292]. With an oxygen permeability of 370 Barrer and an O2/N2 selectivity of 4.0 the PIM-1 shows an extraordinary behavior as a gas-separation polymer. However, long-term measurements revealed a physical aging of PIM-1 analogous to PTMSP, which resulted in reduced permeabilities. When the aging problems can be solved, the PIMs will be a highly interesting polymer class for fabrication of gas-separation membranes. 

Morisato, A., He, Z., and Pinnau, I. (1999). Mixed-gas properties and physical aging of poly(4-methyl-2-pentyne). In B. D. Freeman and I. Pinnau (Eds.), Polymer Membranes for Gas and Vapor Separation Chemistry and Materials Science. ACS Symposium Series 733. American Chemical Society, Washington, DC, pp. 56-67. 

Thin polymer films such as those used in the separation layers of composite gas separation membranes physically age orders of magnitude faster than bulk systems of the same materials [103,104], Zhou et al. [105] performed studies on plasticization and physical aging for perfluorocyclobutyl (PFCB) polymer thin-film composite membranes. 

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