采用分子动力学模拟方法对均苯型PMDA/0DA聚酰亚胺聚合物的关键性能进行了模拟。结果表明:聚合物模型分别经过298 K、200 ps NVT和NPT的动力学模拟后处于动态平衡状态,玻璃化转变温度为606.5 K;由于聚酰亚胺的分子链段随温度升高运动加剧,自由体积减小,因而内聚能密度逐渐减小;在298 K下,杨氏模量、剪切模量、体积模量和泊松比分别为5.12 GPa、1.87 GPa、6.44 GPa和0.37;计算结果与试验数据基本一致,说明分子动力学模拟方法可用于聚酰亚胺聚合物性能的預测。

The key properties of PMDA/ODA polypyromellitimide were simulated by method of molecular dynamics simulation.The results show that the polymer model was in the dynamic equilibrium state after a simulation of 298 K,200 ps NVT and NPT and the glass transition temperature was 606.5 K.The movement of polymer molecular segments become more active and the free volume decreased as the simulation temperature raising,that resulting in the cohesive energy density decreased gradually.The Young's Modulus,Shear Modulus,Volume Modulus and Poisson’s ratio was calculated as 5.12 GPa,1.87 GPa,6.44 GPa and 0.37 at 298 K,respectively.The conclusion were consistent with the experimental results,indicating that the molecular dynamics simulation method could be used to predict the properties of polyimide polymers.