Preparation of phosphoric acid resins with large cation exchange capacities from macroreticular poly(glycidyl methacrylate-co-divinylbenzene) beads and their behavior in uptake of metal ions
✍ Scribed by Akinori Jyo; Satoshi Matsufune; Hidenori Ono; Hiroaki Egawa
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 199 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
In order to prepare phosphoric acid resins (RGPs) with large cation exchange capacities, effects of porosity and cross-linking of the precursory poly(glycidyl methacrylate-co-divinylbenzene) beads on their functionalization with phosphoric acid were studied. Two series of precursory copolymers were prepared: one was prepared by changing the amount of divinylbenzene (1-25 mol %) but by fixing that of isobutyl acetate (porogen) at 140 vol % per monomer mixture; the other by changing the amount of the porogen (40-160 vol %) but by fixing that of the cross-linker at 10 mol %. It was clarified that porosity of the precursors plays an important role in the functionalization. Highly porous precursors were functionalized with high efficiency; for example, even the precursors containing 10 mol % of divinylbenzene resulted in RGPs having cation exchange capacities as large as 6-7 meq/g, so long as BET specific surface areas of the precursors were greater than ca. 30 m 2 /g. The selectivity study has revealed that RGP exhibits the characteristic metal ion selectivity. Lithium ion was adsorbed in preference to sodium and potassium ions; and so-called hard Lewis acid cations, such as uranyl, ferric, and aluminum ions, are adsorbed even from strongly acidic media (1 õ pH õ 2). Among common divalent metal ions, in addition, the resin exhibits the highest selectivity toward lead ion.