Effect of epoxy resin content on the thermal properties of cyanate resin systems

The effects of epoxy resin contents on the curing reaction characteristics,thermal stability and thermal expansion coefficient of cyanate resin systems were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).The results showed that the curing activation energy was reduced effectively by the addition of epoxy resin and the thermal stability and dimensional stability were decreased in different degree.The activation energy and heat-resistant temperature index of modified system with epoxy content 20% were 65.4 kJ/mol and 174 ℃,respectively and decreased by 25.8% and 21.4% compared with that of unmodified cyanate resins.The thermal expansion coefficient of the systems with epoxy content 50% was 65.392 2×10-6/℃ at the range of 25-150 ℃ and increased by 8.13% compared with that of unmodified cyanate resins.