Study on the Modification of Epoxy Resin by a Phosphorus- and Silica-Containing Hybrid

A novel phosphorus- and silica-containing hybrid (DPS) was synthesized by the reaction between diethyl phosphate (DEP) and polyhedral oligomeric siloxanes (POS) formed by hydrolysis condensation of 3-glycidoxypropyltrimethoxysilane (GPTMS). The novel phosphorus-and silica-containing hybrid was characterized by the flourier transform infrared spectroscope (FTIR), silicon nuclear magnetic resonance, and gel permeation chromatography (GPC). Then, the determination of the activation of the reaction between epoxy resin and phosphorus-, and silica-containing hybrids was studied by differential scanning calorimeter (DSC). In the presence of catalyst, the activation energies of the curing reaction were 63.3 and 66.7 kJ/mol calculated by Kis-singer model and Ozawa model respectively. The thermal and flame retardant properties of the cured epoxy modified by DPS were determined by differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), and limited oxygen index (LOI). The results revealed that those properties were improved in comparison with unmodified epoxy resin. In addition, scanning electron microscopy (SEM) was used to investigate the morphology of the cured epoxy resin modified by DPS. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 2213-2219, 2011