Process for manufacturing fluoropolymer membranes

Abstract

The present invention pertains to a process for manufacturing a fluoropolymer membrane, said process comprising the following steps: (i) providing a composition [composition (C)] comprising, preferably consisting of: at least one fluoropolymer [polymer (F)], a water-soluble liquid medium [medium (M)] comprising, preferably consisting of at least one solvent selected from the group consisting of diesters of formula (I-), esteramides of formula (I-) and diamides of formula (I-); R(O═)CO-A-OC(═O)R(I-) RO(O═)C-A-C(═O)NRR(I-) RRN(O═)C-A-C(═O)NRR(I-) wherein: Rand R, equal to or different from each other, are independently selected from the group consisting of C-Chydrocarbon groups; R, R, Rand R, equal to or different from each other, are independently selected from the group consisting of hydrogen, C-Chydrocarbon groups, possibly substituted, being understood that R, R, Rand Rmight be part of a cyclic moiety including the nitrogen atom to which they are bound, said cyclic moiety being possibly substituted and/or possibly comprising one or more than one additional heteroatoms, Ais a C-Cdivalent alkylene group comprising one or more ether oxygen atoms, Aand A, equal to or different from each other, are independently C-Cdivalent alkylene groups, optionally comprising one or more ether oxygen atoms and/or one or more functional side groups; (ii) processing the composition (C) at a temperature of at least 100° C. thereby providing a film; (iii) cooling the film provided in step (ii) to a temperature below 50° C.; (iv) contacting the film provided in step (iii) with a non-solvent medium [medium (M NS)] thereby providing a fluoropolymer membrane; and (v) optionally, drying the fluoropolymer membrane provided in step (iv).