Synthesis, Curing Kinetics and Thermal Stability of Epoxy Resin Containing Benzoxazole Ring

Two kinds of epoxy resin that contain benzoxazole ring, DAROH-O and HOH-O, were prepared. Their molecular structures were confirmed by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) tests. Differential scanning calorimeter (DSC) measurements showed that the apparent activation energy of the curing reaction for the DAROH-O/DDM system was 176.92 kJ/mol and 175.36 kJ/mol calculated by Kissinger method and Ozawa method, respectively. Correspondingly, the apparent activation energy for the HOH-O/DDM system calculated by these two methods was 198.45 kJ/mol and 196.15 kJ/mol, respectively. The thermogravimetric analysis (TG) revealed that the thermal stability of the two epoxy resins were almost the same. The weight loss process includes two stages:the first weight loss occurs at about 350-370℃, and the second weight loss occurs at about 600℃, which is attributed to the decomposition of the benzoxazole ring.