Metal complexes of partially phosphorylated poly(vinyl alcohol) ‐ functions and applications

<jats:title>Abstract</jats:title><jats:p>The highly phosphorylated poly(vinyl alcohol)s (P‐PVAs: degree of phosphorylation 70 mol‐%) were synthesized by the reaction of PVA, dicyandiamide, urea and orthophosphoric acid in DMF solution. A range of P‐PVAs having differents contents (3.3 to 70 mol‐%) of phosphoric acid groups can be obtained by the change of reaction time via the same procedure. The complex formation of Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) ions with P‐PVA thus obtained was investigated by means of potentiometric titration and spectroscopy. By chemical crosslinking reaction of P‐PVA with glutaraldehyde, novel anionic polyelectrolyte gels were easily prepared. The degree of swelling and the hardness of hydro‐gels can be changed by varying the crosslinking reaction condition. The ion exchange capacity and metal ion selectivities of a cation exchange resin prepared from P‐PVA hydrogel have been estimated. Flame‐retardation of metal‐P‐PVA complexes have also studied. The Ni(II)‐P‐PVA complex showed a good flame‐retardation. The molecular composites of the P‐PVA salts of cations such as K<jats:sup>+</jats:sup> or R<jats:sub>4</jats:sub>N<jats:sup>+</jats:sup> (R = CH<jats:sub>3</jats:sub> etc.) were also prepared. These composite polymers showed single ionic conductivity (σ rt > 10<jats:sup>−4</jats:sup> S · cm<jats:sup>−1</jats:sup>).</jats:p>