Engineering ionomeric blends and engineering ionomeric blend membranes

A process for the preparation of acid-base polymer blends or acid-base polymer blend membranes, characterized in that solutions of acidic polymers selected from the group consisting of polymeric sulfonic acids or sulfonic acid salts, polymeric phosphonic acids or phosphonic acid salts, polymeric carboxylic acids or carboxylic acid salts and combinations thereof and a polymer containing basic imidazole, benzimidazole or other heterocyclic, nitrogen-containing basic moieties, are reacted, optionally with the addition of LiCl, in dipolar-aprotic solvents, and the solvent is evaporated from the solutions, wherein the SO3H, PO3H2 or COOH form of the blends is prepared by aftertreating the blend polymer or the blend polymer membrane indiluted mineral acids at temperatures of from 20 to 80° C.