| Graphene has been widely used in friction and lubrication due to its low interlaminar shear force.In addition,because of its unique two-dimensional structure and large specific surface area,graphene-based nanocomposites can be prepared by loading different nanomaterials on its surface,which can play a synergistic role in reducing friction and resisting wear.In this paper,nano-Zirconium dioxide?ZrO2?,nano-copper?Cu?and nano-molybdenum disulfide?MoS2?with different hardness and dimension were compounded with graphene derivatives by different methods,and graphene oxide-based ZrO2nanocomposites?ZrO2@GO?,reduced graphene oxide-based Cu nanocomposites?Cu/RGO?and reduced graphene oxide-based MoS2 nanocomposites?MoS2/RGO?were prepared.Then,on the one hand,ZrO2@GO,Cu/RGO and MoS2/RGO were used as lubricant additives to study their anti-wear properties.On the other hand,the phenolic resin?PF?was modified by ZrO2@GO,Cu/RGO and MoS2/RGO respectively,and the effects of ZrO2@GO,Cu/RGO and MoS2/RGO on the mechanical and tribological properties of PF matrix were studied.The main research contents and conclusions are as follows:?1?ZrO2@GO nanocomposites were prepared by electrostatic self-assembly method,which is convenient,fast and environmentally friendly.The structure and morphology of the nanocomposites were characterized.Then it was used as lubricant additive of liquid paraffin oil to test its wear resistance.It was found that 0.05 wt%ZrO2@GO reduced the friction coefficient and wear rate of liquid paraffin oil by 20.7%and 21.5%,respectively.In addition,the mechanical and tribological properties of ZrO2@GO nano-modified PF composites?ZrO2@GO/PF?were studied.When 1.5 wt%ZrO2@GO was added,the flexural strength,modulus and impact strength of PF increased by 38.6%,8.5%and 8.3%,respectively.When0.5 wt%ZrO2@GO is added,the initial decomposition temperature and the residual content at800?of PF matrix are increased by 20.6%and 17.0%,respectively.In addition,the friction coefficient and wear rate of 0.5 wt%ZrO2@GO/PF are 21.8%and 30.6%lower than those of pure PF,respectively.?2?Cu/RGO nanocomposites were prepared by in-situ reduction method,and their structures and morphologies were characterized.Then it was used as lubricant additive of liquid paraffin oil to test its wear resistance.It was found that 0.2 wt%Cu/RGO reduced the friction coefficient and wear rate of pure liquid paraffin oil by 31.7%and 22.8%,respectively.In addition,the mechanical and tribological properties of Cu/RGO nano-modified PF composites?Cu/RGO/PF?were studied.When 1.0 wt%Cu/RGO was added,the flexural strength,modulus and impact strength of PF decreased by 5.0%,0.1%and 20.4%,respectively.The initial decomposition temperature and the residual content at 800?of PF matrix increased by 22.2%and 22.8%,respectively.In addition,the friction coefficient and wear rate of 2.0 wt%Cu/RGO/PF are 23.7%and 32.5%lower than pure PF,respectively.?3?MoS2/RGO nanocomposites were prepared by one-step hydrothermal method,and their structures and morphologies were characterized.Then it was used as lubricant additive of liquid paraffin oil to test its wear resistance.It was found that 0.10 wt%MoS2/RGO reduced the friction coefficient and wear rate of liquid paraffin oil by 29.9%and 32.6%,respectively.In addition,the mechanical and tribological properties of MoS2/RGO nano-modified PF composites?MoS2/RGO/PF?were studied.When 0.10 wt%MoS2/RGO was added,the flexural strength and modulus of PF increased by 19.6%and 14.7%,the impact strength decreased by 16.7%,and the initial decomposition temperature and the residual content at 800?of PF matrix increased by 20.9%and 12.3%,respectively.In addition,the friction coefficient and wear rate of 0.10 wt%MoS2/RGO/PF are 26.9%and22.9%lower than pure PF,respectively.ZrO2@GO,Cu/RGO and MoS2/RGO as new graphene-based nano-functional composites not only have excellent anti-wear properties,but also greatly improve the mechanical and tribological properties of polymer matrix reinforced by single nano-filler,which provides theoretical basis and technical methods for the design of new generation of high-performance nanocomposites and promotes the application and research of new graphene-based nanocomposites. |
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