Synthesis and Tribological Properties of Bis(2-hydroxyethyl)ammonium Erucate as a Potential Environmentally Friendly Lubricant and Lubricant Additive

Abstract

Recently, environmentally friendly lubricants and their additives have been of great interest. Using such lubricants can provide a few benefits, namely: nontoxicity and biodegradability when exposed to groundwater or soil. Moreover, renewable raw materials could be used to produce these lubricants. This study aims to synthesize bis (2-hydroxyethyl)ammonium erucate protic ionic liquid containing a renewable counterpart-erucic acid. The synthesis of bis (2-hydroxyethyl)ammonium erucate, its physical properties, solubility in the base lubricating fluid, and tribological properties were evaluated. The study shows that even though the investigated protic ionic liquid is liquid at room temperature, it has a very high kinematic viscosity, which drops when the temperature increases. Bis (2-hydroxyethyl)ammonium erucate can be dissolved in water up to 3 wt%. It also has excellent lubricity when used as a neat lubricant and could be successfully applied as a lubricity-enhancing additive in water.