Removal of heavy metal ions using the chelating polymers derived by the condensation of poly(3-hydroxy-4-acetylphenyl methacrylate) with different diamines

A series of methacrylate-based chelating polymers was synthesized by the reaction of 3-hydroxy-4-acetylphenyl methacrylate with amines (e.g., ethylenediamine, propylenediamine, and phenylenediamine) in tetrahydrofuran. The chelating polymers were characterized by infrared (IR) and carbon-13 nuclear magnetic resonance (C-13-NMR) spectroscopic techniques. The thermal stabilities of these polymers were investigated by thermogravimetric (TG) and differential thermal analyses (DTA). Heavy metal ions [viz., Pb(II), Hg(II), Cd(II), and Cr(VI)] were removed with these chelating polymers, and metal ion uptake efficiency, reusability of the resins, and effects of pH and time on the metal removal were also studied. The chelating polymers possess appreciable selectivity for Pb(II) and Hg(II) compared with Cd(II) and Cr(VI). The chelating ability of the polymers towards the heavy metal ions is a sensitive function of the nature of the substituent on the nitrogen atom. The amount of metal uptake by the chelating polymer was determined by atomic absorption spectrophotometry (AAS). (C) 2003 Wiley Periodicals, Inc.