Study on alkylated Schiff base of a triazole with 3, 5-di-tert-butyl-4-hydroxybenzaldehyde as a novel multifunctional lubricant additive

Abstract A novel triazole derived multifunctional lube additive (MFA) denoted as TBB was designed and synthesized for improved metal surface interaction properties and inhibiting lubricant degradation. At first, two hindered phenolic moieties were coupled with the heterocyclic 3,5-diamino-1,2,4-triazole framework by the reaction with 3, 5-di-tert-butyl-4-hydroxybenzaldehyde to give the intermediate Schiff base followed by alkylation through the reaction of bromododecane for better solubility in polyol base oil. After molecular characterization, the TBB performance evaluation for the lubricity and antioxidant characteristics was done following the standard test methods in the polyol. At a low concentration of 1000 ppm, the average wear scar diameter and average friction coefficient was reduced by 16.92% and 64.39% respectively while the RBOT time was increased by 70.76% at 5000 ppm concentration with respect to polol base oil. The standard corrosion testing procedures were used for evaluating the anti-corrosion potential of additive TBB in terms of weight loss, corrosion rate, and penetration rate which were found to be reduced at 5000 ppm concentration to the values as 0.01 ± 0.01 mg, 0.01 ± 0.005 mdd, and 0.001 ± 0.001 mpy from the 0.60 ± 0.04 mg, 0.62 ± 0.03 mdd, and 0.114 ± 0.009 mpy respectively for blank polyol. So TBB showed moderate efficiency as a lubricity improver but showed excellent antioxidant and anti-corrosion additive properties.