Abstract: A silicon-phosphorus hybrid was synthesized thhrough the reaction between 3-glycidoxypropyl trimethoxysilane and phosphoric acid, which was used introduced into a cured epoxy system containing bisphenol-A type epoxy resin and 4,4'-diaminodiphenylmethane. Thermogravimetric analysis, differential scanning calorimetry, and limited oxygen index testing were carried out to characterize the cured products. It was found that the glass transition temperature(Tg) of the cured blends was higher than that of neat epoxy resin, and the thermal stability of the cured blends was lower at low temperature, however, the char yield at 700 ℃of the cured blends was much higher. When the content of silicon-phosphorus hybrid was 30 phr the char yield at 700 ℃ of the curd blends 34.1 %, the Tg was 169 ℃, limited oxygen index was 27.1 %, higher than those of neat epoxy resin by 77.8 %, 9 ℃ and 28 %, respectively.

Key words: epoxy resin, silicon-phosohorus hybrid, flame retardancy, thermal property, cured blend