New chelating polymers for heavy metal ion sorption

Twenty-six new chelating polymers containing pyridyl (Py) or bipyridyl (Bipy) units as ligating centers were synthesized by free-radical reactions of 2-vinylpyridine, 4-vinylpyridine, or 4-methyl-4'-vinyl-2,2'-bipyridine with different dimethacrylate crosslinkers and evaluated for heavy metal ion sorption from aqueous solutions. Both the Py- and Bipy-containing polymers are highly selective for Cu(II) over Co(II) and Ni(II) and for Hg(II) over Cd(II). The polymeric materials with Bipy binding sites generally exhibit more efficient metal ion sorption than do the corresponding Py-containing copolymers. The metal ion sorption capacity of the copolymer also depends on the structure of the dimethacrylate crosslinker. (C) 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 849-856, 1999.