Experimental investigation on the effect of ionic liquids (C16H36BrP and C16H36BrN) on the tribological performance of neem oil

Ionic liquids are liquid salts, widely used in the chemical processing industry and have excellent lubricating properties. The present study focuses on the tribological performance of three different lubricants, pure neem oil, neem oil with 0.5 wt.% of ionic liquid tetrabutylammonium bromide (C16H36BrN) and neem oil with 0.5 wt.% of ionic liquid tetrabutylphosphonium bromide (C16H36BrP) in steel to steel interface. Considerable friction reduction and anti-wear capabilities have been confirmed when neem oil is added with 0.5 wt.% tetrabutylphosphonium bromide. The use of this fluid has reduced the frictional force at a uniform rate, and deep, broad wear scars or blisters or eruptions on the sides of the wear scars are not seen. The viscosity, density and wear resistance values also support this conclusion. The outcome of the research shows that neem oil along with tetrabutylphosphonium bromide can replace the existing conventional, unsustainable hydrocarbon and synthetic-based lubricants.