Rheological Behavior of Biodegradable Lubricants

Biodegradable lubricants are of particular interest from the point of view of environmental protection. Generally, base oils for biodegradable lubricants may be: polyglycols, synthetic ester oils and vegetable oils. The vegetable oils used in this study are: sunflower oil, soybean oil and coconut oil. The rheological study was based on graphical representation of shear velocity based on shear stress using experimental data. The rheological models found in the literature are: Bingham, Casson, Ostwald-de Waele and Herschel-Bulkley. The article proposes three other rheological models of shear speed dependence on shear speed.