Molecular dynamics simulations of tribology properties of NBR (Nitrile-Butadiene Rubber) /carbon nanotube composites

Molecular models containing Fe atoms as the top nanorod and bottom layer and the polymer/carbon nanotube composite as the core are developed to examine the friction coefficient and abrasion rate by sliding the top Fe nanorod on the surface of the polymer matrix subjected to normal loadings. The simulation results indicate that around 38% decrease in an average friction coefficient and 60% decrease in an average abrasion rate of the composites are achieved respectively by introductions of carbon nanotubes. In addition, it is found that the friction coefficient and abrasion rate both experience two stages in the process of loading. The first stage shows a steady fluctuation phrase, while the second indicating an obvious increase in the coefficient and abrasion rate. To help elucidate the findings, the angle, bond energy of the polymer matrix are calculated, and the results are interpreted and discussed accordingly.