Information on the reaction kinetics in the melt is a valuable prerequisite for a successful application of self-healing ability to benzoxazine-based thermosetting resins. The goal of this research was to develop a kinetic model of the Diels–Alder (DA) reaction in a molten state between N -phenylmaleimide (PMI) and benzoxazine-containing furan group (G-f). Rheological data were found to be of significant importance in the kinetic model development and interpretation. The increase in viscosity, the occurrence of side reactions, and equilibrium between DA and r-DA reaction were identified as possible reasons for the deceleration of reaction rate and limiting conversion. After a thorough investigation of the studied system, accompanied by the knowledge from the literature, the potential reason for the incomplete conversion of reactants was reduced to the crossover between chemically and diffusion-controlled reaction due to the increasing viscosity of reaction system. Accordingly, the kinetic model based on the combination of Rabinowitch equation and Chern–Poehlein model was used to accurately describe the progress of the studied reaction in the molten state.

中文翻译：

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熔融态 Diels-Alder 反应的动力学模型：热和粘弹性行为

熔体中反应动力学的信息是将自修复能力成功应用于苯并恶嗪基热固性树脂的重要先决条件。本研究的目的是开发 N-苯基马来酰亚胺 (PMI) 和含苯并恶嗪的呋喃基团 (Gf) 之间熔融状态下狄尔斯-阿尔德 (DA) 反应的动力学模型。发现流变数据在动力学模型的开发和解释中具有重要意义。粘度增加、副反应的发生以及 DA 和 r-DA 反应之间的平衡被确定为反应速率减慢和转化率限制的可能原因。在对所研究的系统进行彻底调查后，结合文献中的知识，由于反应体系的粘度增加，反应物转化不完全的潜在原因被归结为化学反应和扩散控制反应之间的交叉。因此，基于 Rabinowitch 方程和 Chern-Poehlein 模型相结合的动力学模型被用来准确描述熔融状态下所研究反应的进程。