PREPARATION OF AMIDOXIME-FIBER ADSORBENTS BASED ON POLY(METHACRYLONITRILE) FOR RECOVERY OF URANIUM FROM SEAWATER

Polymerization of methacrylonitrile was performed with anionic initiators as reported in the literature. The molecular weight of the polymer produced using BuLi as initiator at 0 +/- 2-degrees-C was on the order of 10(5). Maximum conversion was 97% with BuLi initiator. For comparison, methacrylonitrile was polymerized with diethylmagnesium in dioxane at 70-degrees-C. High-molecular weight polymers with 50-60% conversions were produced by diethylmagnesium initiator. The polymethacrylonitrile obtained by BuLi initiator was used for the fiber production process. The conversion of nitrile was performed by treatment with 3% NH2OH in MeOH at 80-degrees-C. The amidoxime-fiber adsorbent gave a large adsorption rate, such as 176 mug of U/g of adsorbent/day, in a batchwise seawater adsorption test.