Nanomaterial modification of ground tire rubber to improve the properties of recycled rubber: Experiments and molecular dynamics simulations

Abstract Hydrogen peroxide, graphene oxide (GO), and hydroxylated carbon nanotubes (OHCNTs) were used to chemically modify ground tire rubber (GTR) of 40 mesh (40GTR) and 80 mesh (80GTR), which were then blended with styrene‐butadiene rubber (SBR) to prepare recycled rubber and study its mechanical, friction, and damping properties. Compared to SBR/40GTR, the elastic modulus and tensile strength of SBR/80GTR rose by 19.5% and 25.2%, respectively. Compared to SBR/80GTR, the elastic modulus of acid‐oxidized SBR/80GTR (SBR/80GTR‐AO) increased by 2.49%. The mechanical properties of SBR/GTR composites indicated an initial increase followed by a decrease with increasing content of GO or OHCNTs. Among these, the performance enhancement of SBR/GTR‐AO‐GO was most significant. At 1 phr GO, the elastic modulus of SBR/GTR‐AO‐GO composites increased by 9.53%, and the coefficient of friction decreased by 1.74% compared to SBR/GTR. The wear surface morphology and dynamic mechanical properties of the composites were analyzed using scanning electron microscopy and a dynamic mechanical analyzer. Additionally, molecular dynamics simulations elucidated that the mechanical and tribological properties of the modified SBR/GTR composites are enhanced, thereby validating the effectiveness of the modified GTR in reinforcing these properties. Highlights Chemical modification of ground tire rubber (GTR) with diverse particle sizes. Grafting of nanomaterials onto the surface of GTR. Modified GTR improves mechanical properties of recycled rubber. Molecular dynamics simulations of the tensile and tribological properties of recycled rubber.