▎ 摘　　要

NOVELTY - Preparing side chain sulfonated polybenzimidazole composite cation exchange membrane comprises e.g. (1) dissolving polybenzimidazole in a solvent, stirring at 20-60 degrees C for 6-24 hours, and filtering to obtain a polybenzimidazole solution, passing ozone into polybenzimidazole solution for pre-activation, and passing nitrogen after cooling to remove oxygen and ozone, then heating to 80-100 degrees C, adding benzoyl peroxide, and sodium p-styrene sulfonate solution, and carrying out reaction for 2-6 hours under the protection of inert gas, after completing reaction, precipitating reactant with methanol solution, washing and drying to obtain the side chain sulfonated polybenzimidazole, (2) adding side chain sulfonated polybenzimidazole to the solvent and stirring at 20-70 degrees C for 6-12 hours to obtain the sulfonated polybenzimidazole solution, adding sulfonated inorganic substance to the organic solvent to obtain the sulfonated inorganic substance dispersion. USE - The method is useful for preparing side chain sulfonated polybenzimidazole composite cation exchange membrane, which is useful in electrodialysis treatment for treating domestic sewage, sea water and brackish water, food and chemical product processing water (claimed). ADVANTAGE - The membrane: has good ion conductivity, pollution resistance and mechanical stability. The method: is simple, high efficiency, high yield, and controllable artificially film structure. DETAILED DESCRIPTION - Preparing side chain sulfonated polybenzimidazole composite cation exchange membrane comprises (1) dissolving polybenzimidazole in a solvent, stirring at 20-60 degrees C for 6-24 hours, and filtering to obtain a polybenzimidazole solution, passing ozone into polybenzimidazole solution for pre-activation, and passing nitrogen after cooling to remove oxygen and ozone, then heating to 80-100 degrees C, adding benzoyl peroxide, and sodium p-styrene sulfonate solution, and carrying out reaction for 2-6 hours under the protection of inert gas, after completing reaction, precipitating reactant with methanol solution, washing and drying to obtain the side chain sulfonated polybenzimidazole, (2) adding side chain sulfonated polybenzimidazole to the solvent and stirring at 20-70 degrees C for 6-12 hours to obtain the sulfonated polybenzimidazole solution, adding sulfonated inorganic substance to the organic solvent to obtain the sulfonated inorganic substance dispersion, then adding sulfonated inorganic substance dispersion into the sulfonated polybenzimidazole solution and mixing to obtain a composite membrane casting solution, and (3) pouring composite membrane casting solution into a grinding tool, casting into a film, and then drying at 60-80 degrees C for 24-48 hours. An INDEPENDENT CLAIM is also included for side chain sulfonated polybenzimidazole composite cation exchange membrane.