Preparation of Acrylamide Chelating Resins Containing Thiosemicarbazido Groups and Adsorption of Metal Ions on Th e m

Abstract

Chelating resins containing thiosemicarbazido groups as pendant was prepared by the condensation of spherical porous copolymer with thiosemicarbazide and adsorption of metal ions on these resins was studied.
By suspending 30 g of N- (hydroxymethyl) acrylamide and 3.7g of N, N'-methylenediacrylamide in the petroleum hydrocarbon in the presence of water as diluent, the copolymers with the excluded molecular weight of 2 x 10⁴ and the degree of swelling (wet-m//dry-ml) of 2.67were obtained. Chelating resins with the sulfur content of 15.0 wt% were obtained by the condensation of the spherical porous copolymers with thiosemicarbazide in water. For the prepared resins, the pH, the temperature, the ionic strength, and the metalic ion's concentration did not affect the adsorption of Cu²⁺, Ni²⁺, and Pb²⁺within the given limits of experimental conditions. The order of the adsorption was Cu²⁺> Ni >Pb²⁺ under all conditions studied. At the concentration range of 1 x 10^-4mol//, the percentage of Cu²⁺and Ni²⁺ adsorbed on the resins were more than 99% and 94%, respectively. The resins will be utilized for removing trace amounts of heavy metal ions in the presence of a relatively large amount of light metal ions, such as Na⁺ and K⁺.