On the study of cucurbit[6]uril and 4-tert-butylcalix[6]arene as multifunctional lubricant additives

Abstract

The current study describes cucurbit[6]uril and 4-tert-butylcalix[6]arene as high-performance multifunctional additives for polyol lubricant base oils. Cucurbit[6]uril is a macrocyclic compound with an aliphatic core, while 4-tert-butylcalix[6]arene has an aromatic core. The tribological properties of cucurbit[6]uril and 4-tert-butylcalix[6]arene in terms of the friction coefficient and average wear scar diameter were evaluated by the four-ball test (ASTM D4172). The antioxidant properties of these additives were assessed via a universal oxidation test (IP-306) and anticorrosion study by standard ASTM D664. Of the two additives, cucurbit[6]uril shows great promise for applications in industrial areas, maintains excellent tribological ability and exhibits a better load-bearing tribofilm as per morphologies observed by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy.