Synthesis And Research Of Graphene Oxide And Its Composite Material As Water-based Lubrication Additives

As the increasingly severe environmental pollution and energy shortage around the world,environment protection and energy saving get people's more and more attention.Water-based lubricants become the ideal substitute of traditional oil-based lubricants,because of its low pollution,low energy consumption,low cost and excellent security,cooling and cleaning.Currently,the water-based lubricates also have the disadvantages of low friction performance and poor wear resistance,and water-based lubricant additives can improve its anti-friction and anti-wear properties,however,it doesn't have a good effect on improving water-based lubricating performance to use the traditional additives.In the view of this situation,the paper focused on new carbon nanomaterial,studying the fiction and wear properties of graphene oxide?GO?,and synthesized and studied a kind of inorganic/organic composite water-based lubricant additives,in which the GO and acrylate polymer were applied as inorganic and organic materials respectively.In this study,firstly graphite oxide was prepared by the modified Hummers method with natural flake graphite as raw material,and then the GO sheet in deionized water was obtained by ultrasonic stripping the graphite oxide suspension in which its dispersion stability was observed and analysised.The structure of GO was characterized by FT-IR and XRD which results indicate that the GO contained rich oxygen-containing groups and its layer spacing is 0.834nm.The microstructure and thermal properties were characterized by SEM and TG which results indicate that the layers of GO is loose and the surface has many folds,and its thermal performance become poor.Secondly,the friction and wear properties of GO as water-based lubricant additive were tested through the friction and wear testing machine and the factors including the GO concentration,test load and rotate speed were discussed,which influenced friction coefficient and wear rate.The results indicates that the anti-friction and anti-wear properties of pure water are greatly improved by using the GO as water-based lubricant additive,and the friction coefficient and wear rate have reduced significantly with the increase of concentration of GO,which are 0.089 and1.75×10^-4mm³N^-1m^-1 respectively when the concentration is 0.9wt%.And the friction coefficient shows a trend of increase and the wear rate decreases with the increase of load.Both of friction coefficient and wear rate decrease with the increase of rotate speed.The microstructure of worn surface was characterized by SEM and the mechanism of anti-friction and anti-wear was analyzed.Finally,GO/Polymethyl Methacrylate?PMMA?compound emulsion was synthesized through the method of solution polymerization with methyl methacrylate?MMA?as monomer,GO as the additive,potassium persulfate?KPS?as initiator and SDS/OP-10 as compound emulsifier.The best proportion of raw material in reaction was obtained by orthogonal test,and the optimum reaction temperature and reaction time were choose by observing the reaction phenomena.The dispersion stability of compound emulsion was discussed and the solid content and yield of product were calculated.The GO/PMMA compound emulsion was characterized by FT-IR and SEM,which shows that there is a microstructure similar to sandwich in compound emulsion.The friction and wear properties of emulsion was tested and its factors including concentration,load and rotate speed were discussed.The microstrucre of worn surface was characterized by SEM and the mechanism of anti-friction and anti-wear was analyzed.