Abstract:Molecular dynamics simulation was used to study the frictional properties of N-hexadecane base oil added Monooleate Glyceride(GMO) and Polyisobutylsuccinimide-Polyamine(PIBSA-PAM) under shearing at different pressures.The nanogap lubricant model of smooth iron wall was constructed,and the adsorption and self-assembly behaviors of GMO,PIBSA-PAM and the wall surface were described.The density distribution of each molecule and velocity distribution of the lubrication film during the shearing process were analyzed.The friction coefficient was obtained by the output of transverse force and positive force on the surface.The results show that when the lubrication system is compressed to the stable state under different pressures,the density peaks of GMO and PIBSA-PAM near the wall surface are the same as that of N-hexadecane,which indicates that there is competition of adsorption among GMO,PIBSA-PAM and N-hexadecane near the surface.When the lubricating system is sheared at different pressures,the GMO tends to adsorb on the surface,while PIBSA-PAM tends to disperse in the base oil.When the mass fraction of GMO is around 5.0%,N-hexadecane has the minimum friction coefficient of 0.067.
