Polymer–metal complexes of glycine functions supported on N,N′-methylene-bis-acrylamide (NNMBA)-crosslinked polyacrylamides: synthesis, characterisation and catalytic activity

Abstract

Abstract Polyacrylamides with 2–20 mol% NNMBA crosslinks were prepared by the solution polymerisation of the monomers in water. Glycine functions were incorporated by transamidation with excess sodium salt of glycine. Metal ion complexations of these glycine functions in varying structural environments were investigated towards Fe(II), Fe(III), Co(II), Ni(II) and Cu(II) ions. The metal uptake varied in the order: Cu(II)>Ni(II)≈Co(II)>Fe(III)>Fe(II). With increasing degree of crosslinking, the metal uptake increased till 8% crosslinking and decreased further. The metal complexes were characterised by IR and UV spectra. The catalase-like activities of these insoluble metal complexes were investigated by the decomposition of hydrogen peroxide. Co(II) and Cu(II) complexes were found to be effective in the catalytic decomposition of hydrogen peroxide. The catalytic decomposition was found to be first order. The effect of the variables of catalysis like time, temperature, pH, amount of catalyst and the concentration of hydrogen peroxide on the decomposition of hydrogen peroxide were followed. The extent of catalysis varies with the degree of NNMBA crosslinking.