Heterogeneous Cation Exchange Membranes Based on Self-crosslinking Latex Binders

Abstract

The paper deals with the low-cost technology of producing heterogeneous ion-exchange membranes based on latex binder. This technology consists of mixing latex and ion-exchange resin, casting the mixture into molds of desired shapes, and drying membrane foils at room temperature. Effective heterogeneous cation exchange membranes using self-crosslinking styrene-butyl acrylate latexes as alternative binder materials and commercial cation exchange resin as an ion exchange component were prepared. The latexes were synthesized by the semi-continuous emulsion polymerization technique. It has been found that the heterogeneous membranes containing 45–60 wt.% of the commercial cation exchange resin exhibited excellent electro-separation properties in terms of ion-exchange capacity and electric resistance for all types of latex binders, but they suffered from lower permselectivity and higher water-swelling compared to a commercial Ralex^® membrane. In contrast, the self-crosslinking latexes functionalized with 10–15 mol.% of methacrylic acid appear as promising binder materials for the technologically easy production of cation exchange heterogeneous membranes.