Overlooked glassy polymer attributes illustrated by asymmetric polyimide hollow fibers

Gas separation membranes based on glassy polymers often show complex responses to feed compositions, membrane morphologies, and operating conditions. The well-known dual mode sorption and transport models are discussed here as tools to assess plasticization and competition effects in asymmetric morphologies. A framework is illustrated based on these models using polyimide asymmetric hollow fibers. This framework can also be applied to emerging polymer families such as thermally rearranged (TR) and polymers of intrinsic microporosity (PIM), to identify opportunities connected to their innate glassy natures.