硫脲改性聚酰胺固化剂的制备及其性能研究

PREPARATION AND PROPERTIES OF THIOUREA-MODIFIED POLYAMIDE CURING AGENT

为制备与E-51粘度配套的室温快固化聚酰胺类固化剂,使用硫脲改性自制低粘度聚酰胺,探究了最佳反应条件。采用非等温DSC法研究了改性固化剂/E-51的固化反应动力学,并测试了改性前后固化体系的热稳定性。结果表明:硫脲用量为8%,反应温度为100℃,反应时间为1 h时改性固化剂的粘度为10. 9 Pa·s,凝胶时间为23 min,固化时间为47 min,满足使用需求。Kissinger法计算改性固化剂/E-51的固化反应活化能为38. 79 kJ/mol,阿伦尼乌斯常数为9. 68×104,25℃反应速率常数为0. 0154,FWO法计算活化能为42. 73 kJ/mol。改性前后固化体系热分解温度分别为347. 46℃、350. 72℃。

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 9.68×10^4 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.