The present invention concerns a polyester gas separation membrane which is obtained by the interfacial polymerization of benzenetricarbonyl trihalide or benzene tetracarbonyl tetrahalide in a water-insoluble organic solvent in one phase and a variety of polyfunctional phenols present as the di- or tri-salt...http://www.google.es/patents/US5650479?utm_source=gb-gplus-sharePatente US5650479 - Interfacially polymerized polyester films
