Synthesis and Curing Kinetics of O-aminoacetophenone-modified Dicyandiamide Curing Agents for Epoxy Resin

In this study, dicyandiamide (DCD) was modified with o-aminoacetophenone to synthesize a new curing agent for epoxy resin (EP), called o-acetylphenylguanidine (o-APG). The experimental results showed that the yield of o-APG could reach 85.79% under the optimal ratio. The structure of o-APG was characterized via Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis, and nuclear magnetic resonance spectroscopy. The result deduced that the compatibility of o-APG with EP was significantly improved because reacted to form the group. The curing kinetics of the reaction of EP cured with o-APG was investigated via differential scanning calorimetry (DSC) by using the methods of Kissinger, Ozawa, Starink, and Friedman. The DSC analysis result showed that curing temperature was reduced by about 50 °C compared with the DCD-cured EP.