METHOD FOR PRODUCING SULFONATED AROMATIC POLYMERS AND USE OF THE PROCESS PRODUCTS FOR PRODUCING MEMBRANES

摘要

The invention relates to a method for sulfonating aromatic polymers in a gentle manner. The inventive method comprises the following steps: a) dissolving the aromatic polymer in a substantially water-free acid selected from the group consisting of concentrated sulfuric acid, chlorosulfuric acid or oleum, b) adding an organic solvent that is inert under the reaction conditions, c) adding an anhydride of a carboxylic acid, d) adding a sulfonating agent, and e) carrying out the sulfonation at a temperature below 25 DEG C and for a period sufficient to obtain the desired degree of sulfonation. The homogeneous process products obtained can be preferably used in the production of membranes, for example for fuel cell applications.