论文部分内容阅读
采用差示扫描量热法(DSC)在等温条件下对低分子量聚酰胺(PA651)与双酚A型环氧树脂(DGEBA)的固化动力学进行了研究,得到了自催化动力学模型;通过引入临界固化度cα和扩散因子f(α),进一步建立了扩散控制动力学模型。结果表明,早期固化过程具有自催化特征且受化学动力学控制,可用Kamal模型描述。后期固化过程受扩散控制,只能用扩散控制动力学模型描述。研究还发现固化温度越高,体系的最终固化度αmax和cα也越大,扩散控制的影响减小,模型方程与实验结果吻合得越好。
The kinetics of curing of low molecular weight polyamides (PA651) and bisphenol A epoxy resins (DGEBA) was investigated by DSC under isothermal conditions. The autocatalytic kinetic model was obtained. The critical solidification degree cα and diffusion coefficient f (α) were introduced to further establish the diffusion control kinetic model. The results show that the early curing process with autocatalytic characteristics and controlled by the chemical kinetics Kamal model can be described. Post-curing process controlled by diffusion can only be described by diffusion-controlled kinetic model. The study also found that the higher the curing temperature, the higher the final curing degree αmax and cα, the less the effect of diffusion control, the better the model equation agrees with the experimental results.