Study of Novel Ecofriendly Multifunctional Lube Additives Based on Pentaerythritol Phenolic Ester

The concept of an “ecofriendly lubricant” has drawn much attention due to environmental issues related to conventional lubricants. Mere innovations in lube base oils are not enough. The introduction of new ecofriendly additives is also necessary to address such issues. Therefore, there is a need for the development of new multifunctional additives (MFA) that are environmentally benign. In view of this, the mixed esters of pentaerythritol monooleate with gallic acid (additive 1) and 3,5-di-tert-butyl-4-hydroxybenzoic acid (additive 2) have been synthesized. Both additives 1 and 2 were characterized by FT-IR, NMR, TG, and CHNS analyses. They were evaluated for antioxidant and detergent dispersant along with lubricity properties using the rotary bomb oxidation test, blotter spot test, and four ball test. The thermo-oxidative stability of the base oil was found to increase significantly in the presence of additives 1 and 2 at 3000 ppm concentration. The antioxidant, detergent dispersant, and lubricity propert...