Comparative Study of Mechanical and Tribological Properties of Different Fiber‐Reinforced NBR Composites: Experiments and Molecular Dynamics Simulation

To improve the oil swelling resistance and service life of nitrile butadiene rubber (NBR) under oil conditions, the reinforcing effects of glass fiber (GF), basalt fiber (BF), and polyethylene fiber (PE) at varying contents were investigated under normal and swelling conditions. The NBR/GF composites (10 phr) exhibited superior mechanical and tribological properties compared to NBR/BF and NBR/PE composites. The tensile strength and elongation at break of NBR/GF increased to 31.63 MPa and 251%, respectively, while the coefficient of friction (COF) decreased by 13.5% compared to pure NBR. After swelling, the NBR/GF composites maintained a tensile strength of 20.27 MPa, with a 33.7% reduction in elongation at break, and only a 5.93% increase in COF. Microscopic analysis of the wear surface and molecular dynamics simulations revealed the interfacial bonding mechanisms between NBR and fibers, explaining the contribution of fibers to improved mechanical and tribological properties. These findings offer valuable insights for developing NBR composites with enhanced swelling resistance and performance under oil conditions.