Tribological behaviors of composites reinforced by different functionalized carbon nanotube using molecular dynamic simulation

Severe abrasive wear of water-lubricated bearings usually occurs during low-speed and heavy-duty working conditions. To improve the mechanical properties of composites and reduce friction, functionalized carbon nanotubes (CNTs) were added to promote tribological property and reduce the wear rate during rotation against a copper bushing. Ultra High molecular weight polyethylene (UHMWPE) was used as a matrix material, and carboxylic groups (-COOH), amide groups (-CONH2), and phenyl groups (-C6H5) were used to functionalize single-walled nanotubes (SWNTs). The functionalized CNTs were blended with UHMWPE to form composites. Molecular mechanics simulations (MM) and molecular dynamics (MD) simulations are used to investigate interfacial bonding between the functionalized CNTs and matrix materials. Interfacial bonding of functionalized CNTs and tribological property of the composites were investigated using pull-out and confined shear simulations, respectively. The simulation results show that the appropriate functionalization of CNTs could strengthen interfacial bonding between the functionalized CNTs and matrix material. Therefore, the simulative mechanical property of composites has been enhanced and simulated wear rate has been reduced. This study provides a simulative basis for the forward verification test and structural design.