Thermally reversible, amphoteric ion exchange resins consisting of crosslinked microbeads embedded in crosslinked matrix of opposite exchange group type

Abstract

Thermally reversible, amphoteric microbead matrix ion exchange resins of micron size particles of crosslinked, weak acid cation or weak base anion exchange resin embedded in a matrix of a weak ion exchange resin of opposite form are prepared by suspending micron size particles of a weak ion exchange resin in a mixture of monomers which can be converted to a crosslinked matrix polymer, polymerizing the monomers, and then converting the microbead-matrix resin into active ion exchange form with a particle size of about 0.074-4.00 mm. Preferably the resin has microbeads of crosslinked polyacrylic acid embedded in a matrix of polymerized vinylbenzyl chloride - divinylbenzene aminated with dimethyl amine. These amphoteric resins absorb salts from water in a thermally reversible manner with improved resin capacities and kinetics. They have particular utility in the desalination of brackish waters.

Dependencies are inferred from the claim text.