| Because of its excellent adhesive ability, wear resistance, electric insulation performance, mechanical properties, chemical stability, resistant to high temperature properties, epoxy resin have been widely used in automotive, electronics, ships, aircraft, coating, etc. But epoxy resin has obvious disadvantages that toughness insufficiency, the excellent resistance to impact is poor, easy crazing. These shortcomings severely restrict the application of epoxy resin. The demand of rapid development of various materials of epoxy resin characteristics is higher and higher, so, we use a variety of methods to toughen epoxy resin, thus making its application field more extensive.Usually, dicyandiamide (DICY) is epoxy resin latent curing agent, but the curing temperature is high. Sebacic dihydrazide (SDH) has toughened effect on epoxy resin, but in epoxy resin, the solubility and dispersion is very poor. This paper choose different solvents of DICY and SDH respectively, after dissolving, join solvent into epoxy resin, in a relatively short period and at a relatively low temperature, DICY/SDH epoxy resin curing agent is preparation through vacuum distillation, Through the experiments, the most appropriate solvents and the most appropriate experiment scheme is determined, the curing agent is used to cure and toughen epoxy resin curing. Using Fourier infrared spectrometry (FT-IR), optical microscope and quantity of differential scanning calorimetry (DSC) to analysis not curable epoxy resin. Using Fourier infrared spectrometry (FT-IR) and thermo-gravimetric analyzer (TG) to observe and analysis the cured epoxy resin.The experiment results and test results show that, in several solvents, using anhydrous alcohol dissolve dicyandiamide and glycol armour ether dissolve Sebacic dihydrazide has the best results, vacuum distillation using the temperature of 100℃. The light microscope showed that the dispersion of the DICY/SDH curing agent system in not curable epoxy resin is very good, the starting temperature of the curing reaction of epoxy resin mixture is 150℃. The Fourier infrared spectra (FT-IR) showed that in the cured epoxy resin, dicyandiamide and Sebacic dihydrazide react with epoxy resin, peak of epoxy groups disappeared, benzene disappeared, but benzene does not attend the reaction, so the benzene peak still exists. To cured epoxy resin, the result of thermo-gravimetric analyzer (TG) showed that, in the process of curing, when the temperature reaches to 220℃, there is no change in weight, when the temperature reaches to 300C, weight loss is 7%, when the temperature is more than 300℃, there is no change in weight, this showed the system stability is good.
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