竹基多孔碳协同聚磷酸铵阻燃环氧树脂的分子动力学与耗散粒子动力学模拟

Molecular Dynamics and Dissipative Particle Dynamic Simulation on Bamboo-Based Porous Carbon Materials Synergistic Ammonium Polyphosphate Flame Retardant Epoxy Resin

添加剂与基材的相容性是影响复合材料综合性能的重要因素。采用分子模拟技术建立竹基多孔碳材料(PCM)协同聚磷酸铵(APP)复合于环氧树脂(EP)体系的分子模型,利用分子动力学和耗散粒子动力学进行模拟计算;通过实验对模拟结果进行验证。模拟结果表明,与PCM*2相比,表面含有更多含氧活性基团的PCM*1更有利于通过组分之间氢键的形成增强相互作用;与EP/APP/PCM*2(391.9 kJ/mol)相比,EP/APP/PCM*1的结合能显著增大,其值为470.2 kJ/mol,径向分布函数g(r)曲线更高。PCM的介观形貌证明了其表面活性基团有利于组分在EP中的分散,提高了其与基材的相容性。验证结果表明,PCM1的O/C更高,提高了APP在EP中的分散性,EP/APP/PCM1的氧指数达到了27.3%,与未阻燃EP相比,热释放速率峰值降低了45.4%,表征潜在火灾危险性与轰燃性的pk-HRR/TTI值降低至8.6 kW/(m^(2)·s)。分散性的改善使PCM与APP表现出了更好的协同阻燃作用,与分子模拟结果一致。

The compatibility between additive and substrate was an important factor affecting the comprehensive properties of composite materials.The molecular models of bamboo-based porous carbon material(PCM)combined with ammonium polyphosphatred(APP)in epoxy resin(EP)system were established by molecular simulation technology.The simulation calculations,which results were verified by experiments,were carried out by molecular dynamics and dissipative particle dynamics.The simulation results showed that PCM*1 with more oxygen-containing active groups on its surface was more conducive to enhancing the interaction through the formation of hydrogen bonds between components,resulting in an increase in the binding energy of EP/APP/PCM*1 from 391.9 kJ/mol to 470.2 kJ/mol,and the radial distribution function g(r)curve was higher than EP/APP/PCM*2.The mesoscopic morphology further proved that the surface active groups of PCM were beneficial to the dispersion of components in EP,and improved their compatibility with the substrate.The verification results showed that PCM1 with higher O/C promoted the dispersion of APP in EP,the oxygen index of EP/APP/PCM1 reached 27.3%,and the peak heat release rate decreased by 45.4%compared with non-flame retardant EP.The pk-HRR/TTI parameter,which represented potential fire risk and flashover property,was also reduced to 8.6 kW/(m^(2)·s).The improved dispersion resulted in better synergistic flame retardancy between PCM and APP,which was consistent with the results of molecular simulation.