AMIDOXIME RESINS BASED ON POLY(ACRYLONITRILE-CO-VINYLIDENE CHLORIDE-CO-DIVINYLBENZENE) AND THEIR BEHAVIOR IN UPTAKE OF URANIUM FROM SEA-WATER

Amidoxime resins were derived from poly(acrylonitrile-co-vinylidene ch loride-co-divinyl-benzene) beads, which were prepared by suspension po lymerization of the ternary monomeric mixtures in the presence of 4-me thyl-2-pentanone (MIBK) or 1,2-dichloroethane (DCE) as the diluent (po rogen), in order to clarify the effect of copolymerized vinylidene chl oride on properties of the resulting amidoxime resins. Pore structure analyses of the copolymers as well as of their amidoximated derivative s clarified that MIBK yields larger pores than does DCE and then the l atter gives large specific surface areas than does the former. On the other hand, chemical properties of the amidoximated resins, such as an ion-exchange capacities and uranyl ion uptake, were not essentially af fected by the diluent species, indicating that both MIBK and DCE as th e porogen lead to the amidoxime resins with almost the same ability in recovery of uranium from sea water. The uranium recovery decreased wi th increase in the vinylidene chloride content, but the decrease in th e recovery was minor up to the 10 mol % of vinylidene chloride. It was also clarified that the uranium recovery by the amidoxime resins cont aining vinylidene chloride is greatly enhanced by the alkali treatment . (C) 1994 John Wiley & Sons, Inc.