Influence of Composition of Plant Oils on Their Tribological Properties

Sunflower, corn, rapeseed, olive, and linseed oils were used for investigation. Their fatty-acid compositions have been evaluated by gas chromatography. The tribological properties were determined with a four-ball machine. Flash and set points, static and dynamic viscosity of the oils were estimated by standard methods. The results of tests show that refined plant oils possess better tribotechnical properties than the base mineral oil without additives. It was found that their antiwear and bearing resistance properties correlate with the structure of fatty acids molecules. It is demonstrated that the activation of unsaturated bonds as a result of the triglycerides oxidation has a positive influence on friction due to tribopolymerization and film formation on the contact surfaces.