Tribological Properties Of Graphene Nanohybrid Materials Reinforced Epoxy Resin Composites

As a significant branch of thermosetting polymeric-matrix composites,epoxy resin(EP)extensively used in automobiles manufacturing,machines,aerospace,chemical industries and other fields due to it possesses excellent chemical stability,high adhesion and easy processing.However,due to the high brittleness and poor thermal conductivity of EP,its friction coefficient and wear rate are high when used as tribological components.Consequently,the traditional epoxy resin can not meet the requirements of high performance components and harsh working conditions.Graphene,as a typical two-dimensional layered material with strong covalent bonds by sp²hybridization of carbon atoms in the layers and weak van der Waals force and?-?interaction between layers.Therefore,graphene can be used as a solid lubricant to reduce the friction coefficient and wear rate of EP because of its easy sliding under shear force.However,with the development of industrial technology and the diversification of the practical application environment of EP,single reinforced filler can not meet the application requirements of EP composite under various conditions.To overcome the problems of high friction coefficient and poor anti-wear performance of EP,graphene based nanohybrid materials were prepared and used to improve the tribological application of EP.The main research results are as follows:(1)The copper-graphene nanohybrids(Cu-G)was fabricated through the method of space-confined thermal disintegration of copper carbodiimide(CuNCN),and the effect of Cu-G on the tribological properties of EP composites was discussed.Results showed that the presence of Cu-G improved the thermal conductivity and mechanical properties obviously.Wear tests also proved that Cu-G can improve the anti-wear performance of EP composites better than single filler.Compared with the pristine EP,the wear rate of0.5 wt%EP/Cu-G composite was reduced by 66.7%,while the lubrication performance of the composites is not deteriorated.(2)A novel binary hybrid of graphene oxide@tungsten disulfide(WS₂@GO)was prepared via hydrothermal method,and the best dispersion of WS₂@GO was fabricated through changing the concentration of GO.Mechanical and thermal properties testing results shows the tensile strength,toughness and thermal stability of EP/WS₂@GO-2composites are better than pure EP,EP/WS₂ and EP/GO composites,thanks to the hybridization of WS₂ and GO can not only increase the interlayer spacing of GO,but also improve the dispersibility of WS₂ as well as the reaction between GO surface functional groups and the EP matrix increases the bonding strength between the filler and the matrix.Furthermore,tribological test showed that 1.5 wt%WS₂@GO-2reinforced EP composite exhibits the best lubricating performance and anti-wear performance.Compared with pure EP,the friction coefficient and wear rate of the reinforced EP composites decreased by 47.04%and 36.57%respectively.