A molecular dynamics study on the mechanical and tribological behaviors of nitrile butadiene rubber composites reinforced by boron nitride nanotubes

Abstract

To study the enhancing effect of carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) on the mechanical, tribological, and interfacial performances of nitrile butadiene rubber (NBR) matrices, two NBR composite models strengthened by the same weight percentage of CNTs and BNNTs are constructed. The uniaxial tensile test and pull-out simulation are respectively employed to determine the mechanical capacities and interfacial characteristics of the composites. Results indicate that the inclusion of BNNTs can endow the NBR composites with more excellent mechanical properties and better thermal aging resistance compared to that of CNTs. Moreover, about 40.78% higher in the interfacial friction force, 120.7% higher in the interfacial shear strength, and 81.25% higher in the interfacial fracture toughness are achieved for the composites by the addition of BNNTs than those by the addition of CNTs. It is found that BNNTs play a better role in retarding crack propagation. Furthermore, about 23.53% lower in the friction coefficient and 2.36% lower in the abrasion rate can be obtained by the incorporation of BNNTs than by the incorporation of CNTs. To unveil the reinforcing mechanisms on the strengthened mechanical and tribological performances, the interfacial interaction energy, mean coordination number, and radial distribution function of the NBR composites are calculated accordingly. These findings have significant value for the structural design and product development of high-performance rubber composites under extreme working conditions.