Crosslinked copolyimide membranes for phenol recovery from process water by pervaporation.

The effectiveness of different copolyimide membranes in the process of recovering phenol from water by pervaporation has been investigated. The polyimides were obtained by the polycondensation of 6FDA (4,4'-hexafluoro-isopropylidene diphthalic anhydride) with different diamines. The diamines 4 MPD (2,3,5,6-tetramethyl-1,4-phenylene diamine), 6FpDA (4,4'-hexafluoro-isopropylidene dianiline), 6FpODA (4,4'-bis-(4'-aminophenoxyphenyl)-hexafluoropropane), and DABA (3,5-diaminobenzoic acid) as a monomer providing a crosslinkable group, were used.