Synthesis of a new chelate resin for uranium adsorption from seawater. Polystyrene resin containing two amide oxime functions in the repeating unit

Dicyanoethylated polystyrene, poly{1‐[4‐(2,2‐dicyanoethyl)phenyl]ethylene} (2), which was obtained from the reaction of chloromethylated polystyrene, poly[1‐(4‐chloromethylphenyl)‐ethylene] (1) with malononitrile under phase transfer reaction conditions, was treated with hydroxylamine in methanol to afford a polystyrene resin 3 with two amide oxime functions in the repeating unit. Resins 3 exhibit a higher adsorptivity of uranium in seawater than a corresponding resin 5 with one amide oxime function in the repeating unit. The effective adsorption of uranyl ions by resins 3 is attributed to the close proximity of the two amide oxime functions in the styrene monomeric unit, which can effectively coordinate to a uranyl ion.