Polymer-metal complexes of amino functionalized divinylbenzene-crosslinked polyacrylamides

Abstract

The complexation of amino functions supported on polyacrylamides with 2–20 mol% of divinylbenzene (DVB) crosslinks was investigated towards Co(II), Ni(II), Cu(II), Zn(II) and Hg(II) ions. With increasing extent of DVB-crosslinking, the metal ion intake decreased in the order: Hg(II) ≫ Cu(II) > Zn(II) > Ni(II) > Co(II). The polymeric ligand and the derived metal complexes were characterized by their typical i.r. absorptions and from the e.s.r. spectra. The i.r. absorptions of the polymeric ligands were shifted by complexation. The e.s.r. parameters suggested the distorted tetragonal geometry of the Cu(II) complexes. The change in surface morphology on complexation was followed by scanning electron microscopy. The thermal stability varied with the incorporation of metal ions. The activation energy values and the extent of crosslinking in Cu(II) complexes fit into the general equation for a cubic polynomial. The time-course and kinetics of complexation and the adsorption characteristics of complexation were also followed. The swelling characteristics varied with the extent of crosslinking, and the extent of swelling was lower for the complexed resins. The complexed resins can be recycled several times, and the Cu(II)-desorbed resin showed specificity to the Cu(II) ion in the presence of other metal ions.