Synergistic Enhancement of Mechanical and Tribological Properties of Nitrile Butadiene Rubber With RD-Modified GO and CNTs as Antioxidants: Experiments and Molecular Dynamics Simulations

To solve the problems of premature migration and antioxidant failure in rubber, which lead to the low performance of rubber, a combination of molecular dynamics and experimental means was used to study new nano-reinforcement antioxidants. A novel functional nanofiller, namely RDGO, was prepared by grafting 1,2-dihydro-2,2,4-trimethyl-quinoline (antioxidant RD) onto the surface of graphene oxide (GO) using-(2,3-epoxypropoxy) propyltrimethoxysilane (KH560). Five packs of nitrile butadiene rubber (NBR) composites were prepared via mechanical blending with CNTs to synergistically enhance their thermal and oxygen aging, as well as mechanical and tribological properties. The results showed that the compression permanent deformation of NBR/RDGO/CNTs was reduced by approximately 25%, 14%, 17%, and 8%, respectively, compared with the other four groups. The wear surfaces of the NBR composites were characterized using ultra-depth-of-field microscopy and swept-point electron microscopy, and this revealed the synergistic enhancement mechanism of RDGO and CNTs. Molecular dynamics simulations were used to explain the wear mechanisms of the NBR composites from an atomic perspective at 298 K, 374 K, and under cyclohexane dissolution conditions. The synergistic use of the new functionalized nanomaterials, namely RDGO and CNTs, resulted in excellent mechanical and tribological properties of the NBR composites, even during thermal oxygen aging and swelling failure.