Tribological Studies on Two Novel Borate Esters with Nitrogen-Containing Heterocyclic and Alkanolamide as Multifunctional Additives in Rapeseed Oil

Abstract

Borate esters have good load carrying capacity and lubricating properties. However, borate esters are susceptible to hydrolyzation, which limits their applications. To improve the hydrolysis resistance of borate esters, nitrogen-containing heterocyclic and alkanolamide were introduced into their structures. Two novel multifunctional borate esters were synthesized, and their tribological properties were evaluated in rapeseed oil. The two novel borate esters showed superior tribological properties, as well as excellent anti-rust, anti-corrosion, and anti-oxidant properties. During friction, the mixed film containing B₂O₃ and nitrogen-containing organic compounds were formed, iron oxide generated on the worn surface, which were important to anti-wear.

GRAPHICAL ABSTRACT

Keywords:

• Alkanolamide
• borate esters
• heterocyclic
• multifunctional additives
• nitrogen-containing