| Abstract
| - This paper considers the blending of epoxide and diamine components into a glassy polyimide structure(2,2‘-bis(3,4‘-dicarboxyphenyl) hexafluoropropane dianhydride-2,3,5,6-tetramethyl-1,4-phenylenediamine (6FDA-TMPDA) intended for use as a gas separation membrane. It is shown that the diamine component can reactboth with the epoxide component to form an epoxy network and with the polyimide backbone itself, leadingto a complex grafted structure. Bulk density and X-ray diffraction results show that this leads to a denser,more amorphous membrane structure. This effect appears to be independent of the diamine structure. Gaspermeability is reduced and selectivity increases, consistent with established free volume theory. Importantly,however, plasticization resistance also increases. This implies that membrane performance will be more robustwhen exposed to condensable gases such as carbon dioxide. In this particular case, the increase in plasticizationresistance is possibly insufficient to warrant the loss in permeability, particularly when compared to the relativelyhigh permeability measured for diamine−cross-linked polyimide.
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