High ionic conductance ion exchange membranes and their preparation

Abstract

It has been discovered (Examples 4, 11 and 17) that certain desirable films will not absorb a sufficient amount of certain desirable, polymerizable monomers as to result in interpolymer membranes having desirable ion exchange properties after polymerization of any absorbed such monomers and after any subsequent conversion of such absorbed and polymerized monomers into ionizable moieties. It has also been discovered that if a predetermined amount of plasticizer, extractable by such monomers, is incorporated into such films, then the latter will absorb a sufficient amount of such monomers as to result (after polymerization of such monomers) in interpolymer membranes having desirable ion exchange properties. Examples of preferred monomers include the polar (meth) acryloxy and (meth) acrylamido monomers 2-(methacryloxy) ethane sulfonic acid, 2-(acrylamido)-2-methyl propane sulfonic acid, N-(2-methacryloxy ethyl)-N,N-dimethyl amine, N-(3-methacrylamido-propyl)-N,N-dialkyl-N-methyl ammonium halides and N-(2-methacryloxy ethyl)-N,N,N-trimethyl ammonium chloride. Such monomers may be mixed with a minor amount of crosslinking monomer such as divinyl benzene, ethylene glycol dimethacrylate and trimethylol propane trimethacrylate. Preferably any amine moieties in the resulting interpolymer membranes are converted to quaternary ammonium groups.

Dependencies are inferred from the claim text.