Tribological performance evaluation of vegetable lubricant incorporated Ethylene Vinyl Acetate (EVA) and Tertiary-Butyl-Hydroquinone (TBHQ) nanoparticles

Abstract

The adoption of vegetable oil as a basic lubricant has become increasingly prevalent due to growing environmental concerns about the harm caused by lubricants made from petroleum. As a result, many researchers are concentrating on developing new, efficient green lubricants. This current work evaluates the tribological performance of novel ficus carica (fig oil) combined with Ethylene Vinyl Acetate (EVA) viscosity modifier and Tertiary-Butyl-Hydroquinone (TBHQ) nanoparticles as an eco-friendly lubricant. The research employed a four-ball tribometer standard test (ASTM D4172-94). Field emission scanning electron microscopy (FESEM) was used for worn surface morphology examination. In the study, TBHQ was kept at 0.3 mass%, while EVA concentrations varied from 0.5, 1, 1.5, and 5 mass%. An ultrasonic homogenizer was used to combine the samples using the sonication technique. The viscometric study revealed 1 mass% EVA as optimal concentration. Thermogravimetric analysis (TGA) results showed that EVA + TBHQ inclusion resisted lubricant degradation, while oxidation time shift was at onset of 53.5 min against base oil onset of 14.1 min. The frictional results showed 100 kg of load, adding 0.9 mass% EVA + 0.3 mass% TBHQ nanoparticles gives the best reduction in wear and the coefficient of friction, although SAE-5W-30 lubricant performed better. Furthermore, the effectiveness of the added substances was determined by their ability to diffuse into the sliding contact, thereby avoiding direct contact between the sliding bodies, which, if not minimized, could result in machine damage.