On the study of cucurbituril and 4-tert-butylcalixarene as multifunctional lubricant additives†
The current study describes cucurbituril and 4-tert-butylcalixarene as high-performance multifunctional additives for polyol lubricant base oils. Cucurbituril is a macrocyclic compound with an aliphatic core, while 4-tert-butylcalixarene has an aromatic core. The tribological properties of cucurbituril and 4-tert-butylcalixarene 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, cucurbituril 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.