本研究首次在大型聚丙烯（PP）体系上实施反应力场分子动力学（ReaxFF MD），研究了聚丙烯（PP）在加热和恒温过程中的热分解特性，以及热解机理。 PP的讨论。在反应开始时，PP长链的随机CC键断裂导致形成全系列产物。在加热阶段，随着温度的升高，产品成分逐渐向轻组分转变，丙烯的数量明显高于其他产品。在恒温阶段，长期高温导致体系发生二次反应，较重组分含量增加。对两种部分反应途径的观察表明，聚合物链节的随机断裂和链端断裂机制均在 PP 的热分解中起作用。基于模拟数据的热解动力学分析表明，收缩圆柱模型适用于PP热解，PP整体降解的活化能与前人的工作吻合良好。目前的结果将有助于说明 PP 的热解过程并了解其反应机制。PP整体降解的活化能与之前的工作非常吻合。目前的结果将有助于说明 PP 的热解过程并了解其反应机制。PP整体降解的活化能与之前的工作非常吻合。目前的结果将有助于说明 PP 的热解过程并了解其反应机制。

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In this study, reactive force field molecular dynamics (ReaxFF MD) was implemented for the first time on a large polypropylene (PP) system, thermal decomposition characteristics of polypropylene (PP) during both heating and constant temperature process were investigated, and the pyrolysis mechanisms of PP were discussed. At the beginning of the reaction, random C-C bond scission of long PP chains resulted in the formation of a full range of products. In the heating stage, with the increase of the temperature, the product composition gradually shifted to light components and the number of propylene was significantly higher than that of other products. In the constant temperature stage, the long-term high temperature led to the secondary reactions in the system, and the content of heavier components increased. The observation of two partial reaction pathways indicated that both random scission of polymer links and chain-end scission mechanisms played a role in the thermal decomposition of PP. The analysis of pyrolysis kinetics based on simulation data suggested that the Contracting Cylinder model would be suitable for PP pyrolysis, and the activation energy for overall degradation of PP was in good agreement with the previous work. The current results would be helpful in illustrating the pyrolysis processes of PP and understanding its reaction mechanisms.