Electrodialysis membranes comprising sulfonated constituents

Abstract From the Canadian patent

Permselective membranes are disclosed which comprise a layer comprising polystyrene at least a, portion of which is sulfonated and between about 10, wt.% and about 35 wt.% monovinyl arene-hydrogentated diene block copolymer, at least a portion of which is sulfonated. The membranes exhibit a resistance of less than about 8 .OMEGA.-cm2 in 7 wt.% Na2SO4 and an ion exchange capacity of between about 1.0 meq/g and about 1.6 meq/g. Monopolar and bipolar membranes comprising the layer are disclosed. A preferred process for forming the membranes comprises the steps of sulfonating polystyrene and monovinyl arene-hydrogenated diene block copolymer, forming a mixture of the materials in a solvent, …