There is provided an asymmetric integrally skinned membrane comprising a polyimide and another polymer selected from the group consisting of polyvinylpyrrolidone, sulfonated polyetheretherketones and mixtures thereof. The membrane which is substantially insoluble in an organic solvent and substantially...http://www.google.es/patents/US7556677?utm_source=gb-gplus-sharePatente US7556677 - Solvent resistant asymmetric integrally skinned membranes
