Weak acid ion exchangers prepared by graft polymerization of acrylic acid on cross-linked PVA microbeads containing magnetic iron oxide were converted to strong or weak base resins by reaction with glycidyltrimethylammonium chloride or with epichlorohydrin and diethylamine, respectively. Capacities up to 2.6 meq/g were obtained, but the products were susceptible to alkaline hydrolysis. Comparable resins prepared by grafting substituted methacrylic esters hydrolyzed more slowly, indicating that hydrolysis occurred at the ester linkage.