Patent ID: 8377515
Filing Date: 2013-02-19
Classification: B01D,C08F,Y10T

Abstract:
1. A process for preparing a membrane, comprising: (a) applying a fluid composition of sulfonated block copolymer, ester of residual carboxylic acid and non-halogenated aliphatic solvents onto the surface of a substrate, said fluid composition prepared by the steps of: iii. subsequently reacting the residual carboxylic acid contacted with a C1 to C4 alcohol or mixture thereof in a molar ratio of alcohol to residual carboxylic acid of at least 0.9:1 to form the corresponding alkyl esters of the carboxylic acid and to reduce the residual level of the organic residual acid to less than 2.0 wt % based on the total weight of the solution, wherein the reaction mixture is free of any halogenated solvent, (b) spreading the fluid composition to form a uniform thickness layer on the substrate, and (c) allowing the solvent to evaporate from the fluid composition resulting in a solid membrane.