COMPLEX-FORMATION OF PARTIALLY PHOSPHORYLATED POLY(VINYL ALCOHOL), WITH METAL-IONS IN AQUEOUS-SOLUTION

The complex formation of Cr(III), Fe(III), Co(II), Ni(II), Cul(II), an d Zn(II) ions with partially phosphorylated poly(vinyl alcohol) (P-PVA ) in aqueous solution is studied by means of potentiometric titration and electronic as well as e.s.r. spectroscopy. The titration data and spectroscopic results suggest that bivalent and trivalent metal ions b ind with two and three phosphoric acid groups in P-PVA at pH <3.5, res pectively. Overall formation constants, log K, for the bivalent metal ion and P-PVA are about 4.6. The electronic and e.s.r. spectroscopic r esults indicate that cupric ion forms a polynuclear complex of Cu(OH)( 2) solubilized by unreacted hydroxyl groups in P-PVA at pH >6.2. Copyr ight (C) 1996 Elsevier Science Ltd.