Preparation and copolymerization of divalent metal salts of ethylene glycol–methacrylate–maleate

Abstract

Divalent metal salts of ethylene glycol–methacrylate–maleate (EMM) were prepared by the reaction of EMM and divalent metal ions. The divalent metal salts obtained, except for the Ba salt, have melting points which decrease in the order Pb > Ca > Cd > Mg > Zn. The Mg and Ca salts were selected for the copolymerization with MMA, styrene (St), and hydroxyethyl methacrylate. In the copolymerization, the rates of copolymerization increased markedly as the concentration of metal salts increased. Moreover, the systems containing MMA copolymerized more rapidly than those containing St. As for the physical properties of the copolymers obtained, heat distortion temperature, compressive strength, and Rockwell hardness were improved by introducing metal salts into the polymers, and tensile, flexural, and impact strengths are also able to be improved by selecting the most suitable concentration of metal salts according to the species of metal salts and vinyl monomers. Generally, Mg is more effective than Ca in improving the physical properties of the copolymers. Moreover, TGA and boiling water resistance of the copolymers are also discussed.