VAc Free-Radical Polymerization Catalyzed by Copper Alginate Complex Film

A hydrophobic Cu(Ⅱ)-alginate coordination polymer film was prepared by soaking sodium alginate film into 15% CuCl2·2H2O aqueous solution at room temperature over 24 h. The composition, structure and property of Cu(Ⅱ)-alginate as coordination catalyst were studied by ESR, UV-Vis, IR, XPS and electric conductivity methods. It was shown that low spin Cu(Ⅱ) complex was formed as a result of the acceptance of dsp2hydrid orbitals with nonpair electrons transferred from oxygen atoms of two carbonyl hydroxyl groups and negative charge oxygen atoms of two deprotonated carbonyl hydroxyl groups of two alginate chains. The coordination number of center Cu(Ⅱ) in Cu(Ⅱ)-alginate is four. It can be concluded that the vacant site and catalysis active resulted from the distorted tetragonal configuration that was caused by wine and crimp of alginate molecular chain. HSO3-could produce primary free-radical hydrogen by coordination catalysis mechanism, and VAc conducted polymerization by free-radical mechanism, which is different from that of polymerization initiated by CuCl2-Na2SO3-H2O oxidation-reduction system. The induction period for VAc polymerization is 90 s and yield is 82%,mw, mnand mw/mnof PVAc obtained is 1.02×106, 2.27×105and 4.49, respectively.