Performance of silicone modified epoxy resin curable at room temperature

The silicone modified epoxy resin was synthesized by the reaction of a bisphenol A type resin epoxy(E-51) and dihydroxydiphenylsilane(DSPD),a room-temperature and quick curing agent was prepared from polyamide 650 modified with thiourea.The products were tested by IR spectroscopy, the epoxide number of the modified epoxy resin was determined by the hydrochloric acid-acetone method, and the optimum ratio of polyamide 650 and modified polyamide 650 to epoxy resin E-51 was determined by tack free time.The heat resistance of the cured products of modified epoxy resin was characterized by differential scanning calorimetry analysis(DSC) and thermal gravimetric analysis(TG).Moreover,the toughness of the cured products of modified epoxy resin was characterized by tensile test and scanning electron microscopy(SEM).The experimental results showed that the glass transition temperature(T g) of modified epoxy resin was increased by 27℃,the onset temperature of weight loss was increased obviously after curing with polyamide 650,the thermal decomposition temperature for 50% weight loss was 150℃ higher than that of the unmodified epoxy resin,the elongation at break of the cured product increased by 3.41%,in addition,the fracture surface showed obviously the ductile fracture characteristics from SEM images.