PROPERTIES OF PHOSPHORIC ACID RESINS DERIVED FROM POLY (GLYCIDYL METHACRYLATE)S CROSSLINKED WITH DIMETHACRYLATES OF OLIGO(ETHYLENE GLYCOL)S

摘要

Recently, we have reported properties of phosphoric acid resins (RGP), which were prepared by addition of phosphoric acid to epoxy groups in macroreticular poly(glycidyl methacrylate)s crosslinked with divinylbenzene. These resins have larger acid capacities compared with phosphoric acid resins so far reported. For example, even the RGP crosslinked with 10 nominal mol percent of divinylbenzene has an acid capacity as large as 7 meq/g. Furthermore, the metal ion selectivity of RGP is quite different from that of conventional cation exchange resins having sulfonic acid groups. For instance, RGP exhibits extremely high selectivity toward Fe(III), U(VI), and Ti(IV) even in strongly acidic media (1-6 M of mineral acids), which is not observed in the case of the sulfonic acid resins. As reviewed by Helfferich, the metal ion selectivity of crosslinked poly(styrene) based sulfonic acid resins is enhanced with an increase in content of divinylbenzene (or degree of crosslinking). Thus, of interest is the effect of crosslinking species on properties of phosphoric acid resins derived from crosslinked poly (glycidyl methacrylate)s. In this work, we have prepared phosphoric acid resins by addition of phosphoric acid to epoxy groups in poly (glycidyl methacryalte)s crosslinked with dimethacrylates of four kinds of oligo(ethylene glycol)s (Scheme 1), and properties of the resulting resins were studied.