Metal ion interaction of water‐soluble copolymers containing carboxylic acid groups in aqueous phase by membrane filtration technique

Abstract

AbstractThis article reports the synthesis of poly(N‐maleoylglycine‐co‐itaconic acid) by radical copolymerization under different feed mole ratios and its properties to remove various metal ions, such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Pb(II), Cd(II), and Fe(III), in aqueous phase with the liquid‐phase polymer‐based retention(LPR) technique. The interactions of inorganic ions with the hydrophilic water‐soluble polymer were determined as a function of pH and filtration factor. Metal ion retention was found to strongly depend on the pH. Metal ion retention increased as pH and MG content units in the macromolecular backbone increased. The copolymers were characterized by elemental analysis, FTIR, 1H‐NMR, and 13C‐NMR spectroscopy. Additionally, intrinsic viscosity, molecular weight, and polydispersity have been determined for the copolymers. Copolymer and polymer–metal complex thermal behavior was studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques under nitrogen atmosphere. The thermal decomposition temperatures (TDT) were influenced by the copolymer composition. The copolymers present lower TDT than the polymer–metal complex with the same copolymer composition. All copolymers present a single Tg, indicating the formation of random copolymers. A slight deviation of the Tg for the copolymers and its complexes can be observed. The copolymer Tg is higher than the Tg value for the polymer–metal complexes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007