Abstract: In order to prepare room-temperature curing polyamide curing agent with similar viscosity to E-51, thiourea was used to modify the self-made low-viscosity polyamide curing agent, and the optimal reaction conditions were explored. The non-isothermal DSC method was used to study the curing reaction kinetics of the modified curing agent/E-51, and the thermal stability of the cured system before and after the modification was tested. The results showed that, to meet the application requirements, the viscosity of the modified curing agent was 10.9 Pa·s, the gelling time was 23 min, and the curing time was 47 min when the thiourea was 8%, the reaction temperature was 100 ℃, and the reaction time was 1 h. According to the Kissinger method, the activation energy of the modified curing agent/E-51 curing reaction was calculated to be 38.79 kJ/mol, the Arrhenius constant was 9.68×10⁴ and the reaction rate constant was 0.0154 at 25 ℃. According to the FWO method, the activation energy was 42.73 kJ/mol. The thermal decomposition temperatures before and after the modification were 347.46 ℃ and 350.72 ℃, respectively.

Key words: modified polyamide, curing agent, kinetics