Abstract Anion or cation permselective membranes or ion-exchange material is produced by sulphochlorination of a polyolefine, e.g. polyethylene, sheet 0.01-2 mm. thick in heterogeneous reaction so as to produce a water-insoluble product and replacing the chlorine atoms of the sulpho-chloride groups produced by hydroxyl or free basic radicals, e.g. by aminolysis, as required. The sulpho-chlorination may be effected using sulphuryl chloride or sulphur dioxide and chlorine in the presence of a catalyst, e.g. strong acid or Friedel-Crafts, or under irradiation by U.V. or visible light. The hydrolysis or aminolysis may be effected with carbon tetrachloride as swelling agent, using a di- or poly-valent amine for the aminolysis and the non-quaternary amine derivatives may be alkylated and quaternized. Both hydroxyl and free basic radicals may be introduced into the one sheet.
A PROCESS FOR THE PRODUCTION OF PERMSELECTIVE MEMBRANES FOR USE IN ELECTODIALYSIS, WHICH COMPRISES SULFOCHLORINATING A POLYOLEFINE SHEET IN HETEROGENOUS REACTION SO AS TO RESULT IN A SUBSTANTIALLY WATER-INSOLUBLE PRODUCT, SAID POLYOLEFINE BEING SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE AND POLYPROPYLENE AND HAVING A MOLECULAR WEIGHT ABOVE 5000; AND INTRODUCING, IN PLACE OF THE CHLORINE ATOMS OF THE RESULTING PRODUCT, GROUPS SELECTED FROM HYDROXYL AND BASIC GROUPS, TO PRODUCE THEREBY A CATIONEXCHANGE OR AN ANION-EXCHANGE MEMBRANE, RESPECTIVELY, SAID BASIC BEING SELECTED FROM AMINES AND QUATERNARY AMMONIUM DERIVATIVES.
Claim 2
Dependent Claim
88 words
A PROCESS FOR THE PRODUCTION OF PERMSELECTIVE MEMBRANES FOR USE IN ELECTODIALYSIS, WHICH COMPRISES SULFOCHLORINATING A POLYOLEFINE SHEET IN HETEROGENOUS REACTION SO AS TO RESULT IN A SUBSTANTIALLY WATER-INSOLUBLE PRODUCT, SAID POLYOLEFINE BEING SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE AND POLYPROPYLENE AND HAVING A MOLECULAR WEIGHT ABOVE 5000; AND INTRODUCING, IN PLACE OF THE CHLORINE ATOMS OF THE RESULTING PRODUCT, GROUPS SELECTED FROM HYDROXYL AND BASIC GROUPS, TO PRODUCE THEREBY A CATIONEXCHANGE OR AN ANION-EXCHANGE MEMBRANE, RESPECTIVELY, SAID BASIC BEING SELECTED FROM AMINES AND QUATERNARY AMMONIUM DERIVATIVES.