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

Abstract

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.

Keywords

• nitrile rubber
• molecular dynamics simulation
• physical and mechanical property
• butadiene
• microstructure