Friction and wear behavior of chemically modified Sal (Shorea Robusta) oil for bio based lubricant application with effect of CuO nanoparticles

•Discussion of physicochemical properties of Sal oil with CuO nanoparticles as additives.•The Sal oil is epoxidized and CuO nanoparticles are added to the chemically modified oil.•The tribological analysis was performed on pin on disc machine at fixed operating conditions.•Improved frictional and anti-wear mechanism was observed at 0.25% and 0.5% nanoparticles concentration. Due to degradation of the petroleum reserves in the upcoming future and pollution caused by their usage forces industrialists to search for an environmentally friendly option. Sal oil is having sustainability as a bio based lubricant with nanoparticles as additives. This study investigates the friction and wear characteristics of the chemically modified sal oil with epoxidation process. Furthermore, copper oxide nanoparticles (CuO) were added to the modified oil in different proportions. The lubricants were examined for the thermophysical properties like kinematic viscosity, viscosity index increment, flash point, pour point and dispersion stability with tribological analysis. The test was performed by using a pin on disc tribometer by considering different conditions. Based on the specific concentration (percent) of copper oxide nanoparticles, nanolubricants were properly dispersed through ultrasonication process. During the flow behaviour analysis, all the lubricant samples show Newtonian behaviour by presenting a linear relationship between the shear rate and shear stress. Reduced friction and antiwear properties were obtained at 0.25% and 0.5% concentration of copper oxide nanoparticles The Scanning Electron Microscope (SEM) images also shows better surfaces when the nanoparticle was added up to 0.5% concentration.