Glycidyl methacrylate based polymer resins with diethylene triamine tetra acetic acid functions for efficient removal of Ca(II) and Mg(II)

Crosslinked terpolymer beads prepared by suspension polymerization of glyci dyl methacrylate (GMA) (0.4 mol), methyl methacrylate (MMA) (0.5 mol) and d ivinyl benzene (DVB) (0.1 mol) mixtures have been modified through epoxy fu nctions in two steps: (i) by treating with excess of diethylene triamine (D ETA); and (ii) by subsequent reaction with potassium chloroacetate. The res ulting polymer possessing diethylene triamine tetra acetic acid (DT-FA) fun ctions (with degree of functionalization DF: 1.70 mmol.g(-1)) is an efficie nt sorbent for removal of Ca (II) and Mg (II) ions in ppm levels. Interesti ngly when the sodium form of the resin is used in relatively high concentra tions (0.1 M) sorbed amounts will be 10-45% in excess of the theoretical ca pacity due to precipitation of the metal hydroxides on polymer particles be side chelation with the metal ions. Having EDTA-like chelating units, the p olymer is able to absorb also heavy metal ions such as Fe (III), Zn (II), C d (II), Pb (II), Ni (II), Cu (II), Co (II) ions. Not having hydrolysable li nkages, metal-free resins can be obtained by acid treatment (4 M HCl) witho ut loosing its activity. The resin with DTTA functions seems to be applicab le in large scale water softening processes. (C) 2001 Published by Elsevier Science B.V.