Synthesis and characterization of epoxy resin in the presence of the p-bromophenacyl dimethylsulfonium ylide-mercuric chloride complex

Abstract

Modified epoxy resins have been synthesized by reacting a 1 : 10 mole ratio of bisphenol-A and epichlorohydrin in the presence of the p-bromophenacyl dimethylsulfonium ylide-mercuric chloride complex at 30 • C. The value(s) for the epoxide equivalent weight and chlorine content are higher for the modified epoxy resin than for the control epoxy resin. The hydroxyl content, viscosity, and refractive indices are smaller than the control values. DSC studies show that percentage crystallinity (50% and 70%), degree of cure (α ) (0.62 and 0.84), and the glass transition temperature (T g ) (278 • C and 302 • C) of the modified epoxy resins are higher than those of the control epoxy resin. The p-bromophenacyl dimethylsulfonium ylide-mercuric chloride complex modifies and cures the epoxy resin simultaneously. The activation energy, determined from TGA, is 86 kJ/ mol and the reaction shows first-order kinetics.