PROCESS FOR MANUFACTURING FLUOROPOLYMER MEMBRANES

摘要

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 (Mws)] comprising, preferably consisting of, at least one solvent selected from the group consisting of diesters of formula (I-de), esteramides of formula (l-ea) and diamides of formula (l-da): R1 (O=)CO-Ade-OC(=O)R2 (l-de) R1O(O=)C-Aea-C(=O)NR3R4 (l-ea) R5R6N(O=)C-Ada-C(=O)NR5R6 (l-da) wherein: - R1 and R2, equal to or different from each other, are independently selected from the group consisting of C1-C20 hydrocarbon groups; - R3, R4, R5 and R6, equal to or different from each other, are independently selected from the group consisting of hydrogen, C1-C36 hydrocarbon groups, possibly substituted, being understood that R3, R4, R5 and R6 might 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, - Ade is a C3-C10 divalent alkylene group comprising one or more ether oxygen atoms, - Aea and Ada, equal to or different from each other, are independently C3-C10 divalent 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).