p-Chlorophenylmaleimide and p-hydroxy-phenylmaleimide with 2-hydroxypropyl methacrylate were synthesized by radical polymerization, and the metal ion retention capacity and thermal behavior of the copolymers were evaluated. The copolymers were obtained by solution radical polymerization with a 0.50: 0.50 feed monomer ratio. The maximum retention capacity (MRC) for the removal of two metal ions, Co(II) and Ni(II) in aqueous phase were determined using the Equid-phase polymer based retention technique. Inorganic ion interactions with the hydrophilic polymer were determined as a function of pH. The metal ion retention capacity does not depend strongly on the pH. Metal ion retention increased with an increase of pH for a copolymer composition 0.50 : 0.50. At different pH, the MRC of the poly(p-chlorophenylmaleimide-co-2-hydroxypropylmetha-crylate) for Co(II) and Ni(II) ions varied from 44.1 to 48.6 mg/g and from 41.5 mg/g to 46.0 mg/g, respectively; while the MRC of poly(p-hydroxyphenylmaleimide-co-2-hydroxy-propyl methacrylate) for Co(If) and Ni(II) ions varied from 28.4 to 35.6 mg/g and from 27.2 to 30.8 mg/g, respectively. The copolymers and copolymer-metal complexes were characterized by elemental analysis, FT-IR, H-1 NMR spectroscopy, and thermal behavior. The thermal behavior of the copolymer and polymer-metal complexes were studied using differential scanning calorimetry and thermogravimetry techniques under nitrogen atmosphere. The thermal decomposition temperature and T-g were influenced by the binding-metal ion on the copolymer. (c) 2007 Wiley Periodicals.