Boundary and elastohydrodynamic lubrication studies of glycerol aqueous solutions as green lubricants

• The friction coefficient of pure glycerol is decreased by adding some water.
• The friction coefficient of glycerol aqueous solutions is much lower than that of rapeseed oil.
• The anti-wear property of pure glycerol is lower than that of rapeseed oil.
• Glycerol aqueous solutions have great potential as green lubricants.

In this paper, the boundary and elastohydrodynamic lubricating behaviour of glycerol and its aqueous solutions are discussed in both rolling and sliding contacts with a view on assessing the use of glycerol as a green lubricant. To understand the lubricating mechanism, the film thickness of glycerol and its aqueous solutions were studied at different velocities. The results show that the viscosity of glycerol can be controlled for a wide range by adding different amounts of water. The lubricating behaviour of glycerol in all lubricating regimes can be improved by adding water. The results suggest that glycerol aqueous solutions have great potential to replace rapeseed oils as environmentally friendly base oils in several applications.

The friction coefficient of glycerol aqueous solutions is obviously lower than that of rapeseed oil, which suggests that glycerol aqueous solutions have great potential to replace rapeseed oils as environmentally friendly base oils in some applications.Figure optionsDownload high-quality image (306 K)Download as PowerPoint slide