Carbamoylmethylphosphine oxide functionalised porous crosslinked polymers towards sequential separation of uranium (VI) and thorium (IV)

A new class of highly crosslinked porous polymeric materials with an ethylene glycol dimethacrylate (EGDMA) backbone appended with carbamoylmethylphosphineoxide (CMPO) ligands has been synthesized via precipitation polymerization. The polymers were characterized by CP-MAS NMR, FT-IR, DSC-TGA, SEM and elemental analysis. The polymers prepared in various porogens were evaluated by nitrogen adsorption/desorption experiments, which revealed the existence of large pore volume and surface areas. The ability of polymers to extract actinides (U, Th, Am) utilizing solid phase extraction (SPE) strategy by batch sorption methods as a function of nitric acid concentration are studied. The crosslinked polymers show - a good sorption ability towards U(VI), Th(IV) and Am(III); - selective extraction of U(VI) over Th(IV); and -high radiolytic stability towards gamma radiation. The effect of porogen on pore structure, sorption kinetics, metal loading, release behavior and recycling studies were also discussed. Sequential and selective separation of U(VI) and Th(IV) was demonstrated by extraction chromatography.