## 3 Results and Discussion
### Effect of Curing Agent MC120D on Reaction Kinetics  
The differential thermal curves of the system with the imidazole curing agent MC120D at a content of 10 to 50%, and a BGE content fixed at 17.5% are shown in Figure 4. The results that are shown in Figure 4, as well as those shown in Figure 2C, reveal that the differential thermal curves have two exothermic peaks for the MC120D content of 10% and 20%, whereas they have only one exothermic peak for the MC120D content of 30 to 50%. This finding indicates that the curing reaction of MC120D in a certain concentration range is a two-stage reaction. Once a certain amount is exceeded, the resin curing occurs in a one-step reaction. However, the reaction mechanism needs to be further studied. Like the situation for BGE, for different dosages of MC120D, as the heating rate increases, the initial temperature, peak temperature, and termination temperature also move toward the high temperature direction, and the higher the heating rate, the sharper the exothermic peak. The results presented in Figure 5 show that the plots of \(-\ln(\beta/T_{P}{}^{2})\) vs. \(1000/T_{P}\), and \(-\ln\beta\) vs. \(1000/T_{P}\) at different heating rates have a good linear relationship with the different amounts of MC120D, which findings are consistent with the kinetic analysis based on the Kissinger and Crane equations, respectively. Like in the case of BGE, the activation energy and reaction order with different mass fractions of the catalyst, and the kinetic parameters of the curing reaction with different dosages of MC120D were obtained and they are shown in Tables 3 and 4. The data listed in Table 3 reveal that the activation energy reached its lowest value of 46.73 (kJ mol\({}^{-1}\)) when the content of MC120D was 20%, indicating that the reactivity at this time reaches its maximum, which is consistent with the results presented in Table 1.  
The data presented in Table 4, which were obtained by keeping the BGE content unchanged at 17.5%, show that the value of A for the MC120D content of 20% is much smaller than those for other MC120D contents under different heating rates. This finding indicates that the curing performance of the epoxy resin system reaches its best performance under this condition, which is consistent with the above results. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**BGE Fraction (\%)** & \(\beta\) (K-min\({}^{-1}\)) & \(T_{i}\) (K) & \(T_{P}\) (K) & \(T_{f}\) (K) & \(A\) (1/s) & \(k\) \\ \hline \multirow{4}{*}{10} & 5 & 347.3 & 407.3 & 447.3 & \(2.19\times 10^{5}\) & 0.17 \\  & 10 & 360.0 & 425.0 & 470.0 & \(2.24\times 10^{5}\) & 0.32 \\  & 15 & 366.0 & 436.0 & 481.0 & \(2.27\times 10^{5}\) & 0.45 \\  & 20 & 376.1 & 446.1 & 481.1 & \(2.15\times 10^{5}\) & 0.58 \\ \hline \multirow{4}{*}{12.5} & 5 & 353.2 & 407.0 & 522.0 & \(1.94\times 10^{6}\) & 0.20 \\  & 10 & 363.2 & 423.2 & 533.2 & \(1.93\times 10^{6}\) & 0.37 \\  & 15 & 376.3 & 436.3 & 546.3 & \(1.71\times 10^{6}\) & 0.52 \\  & 20 & 352.8 & 437.8 & 552.8 & \(2.16\times 10^{6}\) & 0.68 \\ \hline \multirow{4}{*}{15.0} & 5 & 348.0 & 408.2 & 448.2 & \(5.13\times 10^{5}\) & 0.18 \\  & 10 & 363.0 & 424.1 & 468.0 & \(5.45\times 10^{5}\) & 0.34 \\  & 15 & 361.7 & 436.7 & 476.7 & \(5.10\times 10^{5}\) & 0.48 \\  & 20 & 339.1 & 444.1 & 479.1 & \(5.22\times 10^{5}\) & 0.61 \\ \hline \multirow{4}{*}{17.5} & 5 & 345.3 & 408.5 & 448.5 & \(1.59\times 10^{5}\) & 0.17 \\  & 10 & 363.1 & 425.3 & 470.3 & \(1.70\times 10^{5}\) & 0.31 \\  & 15 & 363.1 & 438.1 & 478.1 & \(1.64\times 10^{5}\) & 0.44 \\  & 20 & 372.7 & 447.7 & 482.7 & \(1.59\times 10^In the previous tests, the components of the core healing agent and curing agent were investigated. Whereas the microcapsule itself has not been involved, although the self-healing function is realized by the microcapsules.