Abstract: The epoxy resin was modified by bisphenl-A dicyanate, and the glass fiber reinforced composites were prepared. The effect of the different mass ratio epoxy resin/cyanate ester resin on the co-cured product structure and glass transition temperature were investigated by fourier transform infrared spectroscopy (FT-IR) and dynamic mechanical analysis (DMA), tensile property, flexural property and moisture absorption property of the composites were discussed. The results show that, with the increasing of the content of triazine ring, the content of oxazolidinone decreases as cyanate ester resin increases. When the mass ratio epoxy resin/cyanate ester resin is 50/50, the glass transition temperature of the composite is 215.6℃ and increases by 49.7℃compared to unmodified epoxy resin. After 650 h, water absorption is only 0.69%, but the tensile strength and flexural strength decrease slightly. Scanning electron microscopy (SEM) shows that the residual stress of composites increase with the incorporation of cyanate ester resin, and composites exhibit brittle fracture.

Key words: epoxy resin, cyanate ester resin, heat resistance, mechanical properties, moisture absorption properties