Comparative study of the thermal properties of Sesame oil and two mineral oils of different viscosity

Abstract

Introduction: In recent years the research and development of biolubricants from vegetable oils has increased to minimize the impact on the environment of petroleum derivatives. Objective: In this work, there was realized a comparative study of the thermal properties of the oil of Sesame with those of two mineral oils, of medium and high viscosity (360 and 255), which were free of additives. Method: The characterization of the three oils was performed using the technique of infrared spectroscopy (FT-IR) and physical properties such as kinematic viscosity, density, thermal and oxidative properties were determined by the analysis of Differential Calorimetry Scanning (DSC). Results: The sesame oil had a pour point of – 14.67 ° C, lower temperature than for mineral oils of 255 and 360, (– 4.29 ° C and – 6.89 ° C, respectively). The high content of unsaturated fatty acids (84.86%) could be responsible for this behavior. The oils were stable to temperatures near to 250 °C and with nitrogen atmosphere. Mineral oils were more stable to oxidation because of their high content of fatty acids with saturated hydrocarbon chains which it had no oxidizable sites. Conclusions: Nevertheless, the low stability of sesame oil is due to the high content of unsaturated fatty acids, the use of antioxidant, additive or a chemical modification of the unsaturated chains, this property might be improved to use the oil as a lubricant.