聚酰亚胺高温热解反应的分子动力学模拟

摘要

使用ReaxFF分子动力学(ReaxFF-MD)模拟方法研究聚酰亚胺固化物在3000、3500和4000 K温度下的热裂解特性.结果表明,热解的引发反应主要是酰胺键的断裂,热解的主要产物是H2O、H2和大分子碳团簇,同时观察到少量CO、HCN和N 2等小分子.当反应温度升高,裂解速度加快,其中H 2生成速率明显加快.分别观察到H2O和H2的2种主要生成途径.反应过程中可以观察到类似石墨烯结构的碳团簇的形成.使用ReaxFF方法模拟聚酰亚胺高温热解可以得到与实际实验相一致的结果并能跟踪反应过程.%The curing polyimide pyrolysis characteristics in different temperature were simulated by ReaxFF dynamics method. The results showed that the cleavage of amide bond are the beginning of the reaction. The main product of pyrolysis is H2O,H2 and macro-molecular carbon clusters. In addition,we also found other small molecular products,such as N2 ,HCN and CO. Polyimide cracking rate is accelerated as the temperature rises. The generation rate of H 2 is significantly increasing. Two main generating ways of H2O and H2 were observed. The larger carbon cluster containing graphene-related structure are generated in the reaction process. In this paper, the results which simulated by ReaxFF dynamics method are the same as the actual experimental results. The ReaxFF dynamics method can provide useful insights into the organic materials thermal decomposition under high-temperature.