杜仲胶/天然橡胶共混物的分子动力学模拟和耗散粒子动力学模拟

应用分子动力学(MD)和耗散粒子动力学(DPD)模拟方法对杜仲胶(TPI)、天然橡胶(NR)的相容性进行了研究。采用MD模拟方法,在COMPASS力场下,对纯物质在不同聚合度下的溶度参数、一系列共混比的TPI/NR共混物内聚能密度、Flory-Huggins作用参数进行了模拟计算,确定了纯物质单链的聚合度,经判断各比例共混物的相容性均较好;采用DPD模拟方法对TPI/NR共混体系的相结构进行了研究,从等密度图可以进一步判断共混体系的相容性;分析比较两种纯物质的径向分布函数,揭示了其相互作用的本质;经过分析比较静态力学性能,发现共混比为1/3的TPI/NR共混物性能最佳,其结论与实验结果一致。

Molecular Dynamics and Dissipative Particle Dynamics Simulation of TPI/NR Blends

Compatibility of TPI and NR blends was calculated by the application of molecular dynamics(MD) and dissipative particle dynamics(DPD) simulation method.The solubility parameters(δ) verse of the different repetitive units of pure substances was calculated by MD simulations with the COMPASS force field and determined a suita-ble one.The cohesive energy density(CED) and Flory-Huggins interaction parameter(χ) in a series of blend ratio of the TPI /NR blends were computed by MD simulations to predict blend miscibility.It was found that the miscibility of entire range TPI/NR blends were well.The phase structure of the TPI/NR blends was simulated by DPD approach.The compatibility of the blends could be further analyse from the density profiles.The two pair correlation function of pure substances were compared and the nature of their interactions was revealed.Static mechanical properties were analyzed,found that 1/3 blend compositions of TPI/NR was best.Results are correlated well with the reported data.