Evaluation of lubricant properties of bio-lubricant formulations developed from neem seed oil

The use of petroleum products as lubricants has already created a large number of environmental problems and this creates the importance of the search for environment-friendly vegetable oils. This study evaluates and compares the lubricant properties of neem seed oil with various proportions of stearic acid and low-density polyethylene (LDPE) separately as additives and compared with the mineral oil, SAE20W40. The bio-lubricant formulation of neem seed oil with 2% stearic acid reduced the wear scar diameter (WSD) of the base oil by 30%, and the coefficient of friction (COF) by 46.3%. At the same time, LDPE does not have a major role in varying the tribological property. The addition of LDPE had outstanding effects on improving the viscosity of neem seed oil whereas stearic acid did not improve the viscosity of the base oil considerably. The cold flow properties of the samples were evaluated using differential scanning calorimetry (DSC).