Gas separation membranes obtained by partial pyrolysis of polyimides exhibiting polyethylene oxide moieties

Aromatic copolyimides (PIx) and aromatic-aliphatic (PIxEOy) were synthesized by reacting 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with mixtures obtained from 2,2′-bis(4-aminophenyl)hexafluoropropane (6FpDA), 5-diaminobenzoic acid (DABA) Jeffamine ED-2003 (PEO). The selective thermal removal of PEO PIxEOy yielded membranes high stability good mechanical properties. presence carboxylic groups minimized the shrinkage during cross-linking process. containing 10 mol% DABA exhibited O2/N2 CO2/CH4 separation performance, resistance to CO2 plasticization. PIx/PIxEOy blends less than wt% prepared. selectivity/permeability balance cross-linked largely exceeded that PIx. results highlight a possible strategy for using analogous cross-linkable polymers exhibiting ethylene oxide moieties as mere additive prepare free volume polyimide's membranes, enhanced properties