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 ca...