用分子动力学模拟研究丁二烯微观结构对丁腈橡胶物理机械性能的影响

采用分子动力学模拟的方法对基于3种不同丁二烯键合结构建立的丁腈橡胶模型(A、B、C模型)进行了模拟计算,以考察丁二烯微观结构对丁腈橡胶物理机械性能的影响.采用恒定应变法计算模型的物理机械性能,然后将模型与铁原子层结合建立摩擦副模型,利用剪切模拟分析丁腈橡胶摩擦过程的磨损机理.结果表明,与A模型和C模型相比,B模型分子链...

Studies on effect of butadiene microstructure on physical and mechanical properties of nitrile rubber by molecular dynamics simulation

Three kinds of nitrile rubber (NBR) models (A, B and C model) with different butadiene bon-ding structures were simulated by molecular dynamics simulation to investigate the effect of butadiene microstructure on the physical and mechanical properties of NBR. The physical and mechanical properties of the model were calculated by the constant strain method, and then the friction pair model was established by combining the model with the iron atom layer. The wear mechanism of NBR friction process was analyzed by shear simulation. The results showed that compared with model A and model C, the molecular chain of model B contained five trans-1,4-butadiene monomers and five 1,2-buta-diene monomers. Its elastic modulus was 13% and 7% higher, and the friction coefficient was reduced by 18% and 8% respectively. In this model, vinyl group enhanced the interaction of polymer matrix. Compared with cis-1,4-butadiene, trans-1,4-buta-diene was more conducive to the stability of polymer matrix structure. Therefore, model B had better physical and mechanical properties.