The Influence of the Ethyl Oleate and n-Hexane Mixture on the Wetting and Lubricant Properties of Canola Oil

Canola oil (RO) is increasingly being considered as a potential lubricant for various types of abrasive materials. Unfortunately, its properties such as wettability, surface tension (ST), adhesion work and dynamic viscosity do not always meet the requirements of a lubricant. Therefore, these properties of RO were modified by adding n-hexane (Hex) and ethyl oleate (EO) to it and the result was analyzed based on the contact angle measurements as well as values of surface tension and dynamic viscosity. Contact angle, being a measure of wetting properties, was determined for RO + Hex, RO + EO, EO + Hex and RO + Hex + EO mixtures on polytetrafluoroethylene (PTFE), poly (methyl methacrylate) (PMMA) and steel. The obtained results allowed for the determination of the components and parameters of the surface tension of the tested mixtures and then the adhesion work of these mixtures to PTFE, PMMA and steel. Then, using different approaches to the work of adhesion, the pressure of the adsorption layer on the PMMA and steel surfaces was determined, which has a significant impact on the wettability of these solids. It was found that the addition of Hex to RO reduces its surface tension, adhesion work and dynamic viscosity and increases the wetting properties of RO. Adding EO to RO slightly lowers its surface tension, greatly decreases its dynamic viscosity and has minimal impact on its adhesive and wetting characteristics. When both EO and Hex are added to RO together, the resulting mixture achieves optimal values for the parameters that influence RO’s lubrication properties.