Improving tribological performance of porous oil-impregnated GO/PA6 composites with double lubrication structure

Using carbon nanomaterials to construct self-lubricating polymer materials with porous self-lubricating structures has become an effective way to improve the tribological performance of polymer composites. The synergistic effect between 1.0 wt% graphene oxide (GO) and lubricating oil resulted in excellent tribological properties of polyamide 6 (PA6) composites under different loads and speeds. It indicated that the introduction of GO in porous PA6 matrix (GO/PA6) would provide enhanced tribological performance with the friction coefficient reduction by 23.4% and wear resistance improvement by 36.2%. This was explained by the lubricating oil stored in the pores of PA6 material would be released to the surface of the matrix material under the dual effect of load and temperature during the friction process. The released lubricating oil would formed a solid-liquid double lubrication structure with the well-dispersed GO in the matrix, thus the porous oil-immersed GO/PA6 composite materials demonstrates excellent tribological performance. This work provides a solid-liquid double lubrication strategy for enhancing the tribological properties of self-lubricating polymers, which would promote the self-lubricating polymer composites more widely applied in the field of friction materials.