Molecular dynamics simulation of mechanical and tribological properties of nitrile butadiene rubber with different length and content carbon nanotubes

Nitrile butadiene rubber is attracting attention as an essential elastic material in the automobile, aviation, pe-troleum, and printing industries. However, the effects of carbon nanotubes (CNTS) with different contents and lengths on mechanical and tribological properties of nitrile butadiene rubber are rarely reported. Therefore, we aim to elucidate the microscopic strengthening mechanism of NBR matrix by changing the content and length of CNTS from an atomic perspective. Specifically, the effects of CNTS (5 wt%, 9 wt%, 13 wt% and 17 wt%) and CNTS (2.130 nm, 2.556 nm and 2.982 nm) on mechanical and tribological properties of butadiene rubber composites are investigated by molecular dynamics simulation. The experimental results show that the me-chanical properties of the composites increase first and then decrease with the increase of CNTS content. In addition, the shear resistance of the composites is improved with the increase of CNTS content, and the com-posites containing 13 wt% CNTS showed relatively excellent friction properties. Moreover, the mechanical and frictional properties of the composites are improved with the increase of the length of CNTS. It is determined that the increasing length of CNTS also enhances the interaction between CNTS and the molecular chains of nitrile butadiene rubber, which improves the compactness and shear deformation resistance of the composite.