Synthesis and evaluation of a protic ionic liquid as a multifunctional lubricant additive

Abstract

An oil soluble multifunctional protic ionic liquid (IL) was synthesized and its tribological and antioxidant properties in poly alpha olefin (PAO4) were investigated. The tribological results demonstrated that the IL significantly reduced friction and wear of PAO4. The PAO4 blend with IL resulted in an induced oxidation time of 555 min which is 8.2 and 3.5 times higher than that of pure PAO4 and PAO4 with zinc dialkyl dithiophosphate (ZDDP) for the rotating pressure vessel oxidation test. It is likely that free nonylated diphenylamine acted as a radical scavenger to enhance antioxidant performance, while free bis(2-ethylhexyl) phosphate was more prone to adsorb and react with the metal surface to form a phosphorus-rich tribofilm in order to protect the rubbing surface.

Influence of a halogen free ionic liquid on the rheological and tribological characteristics of canola oil

“…Yang et al (2018) investigated lithium bis(trifluoromethanesulfonyl) imide in 0, 1, 3 and 5 Wt.% with polyethylene glycol and found excellent tribological performance in boundary lubrication regime. Jiang et al (2020) synthesized an oil-miscible IL and investigated its tribological and antioxidant properties in polyalphaolefin (PAO4). The friction and wear were reduced considerably with addition of IL in PAO4.…”

Synthesis and investigation of phosphorus-free ionic liquids as multifunctional lubricating additives

“…15 Our recent work reported a multifunctional protic IL which was effective friction-reducing and anti-wear agent in polyalpha olefin (PAO4), in addition, it also exhibited excellent antioxidant properties due to the presence of diphenylamine group. 16 However, in order to achieve better tribological properties, most of the previously reported ILs reported contained phosphorus, halogen, or sulfur elements which could be harmful to the environment. 17–19 Fatty acids are the renewable, green, and sustainable source, and have been used to reduce the friction coefficient and synthesize protic ionic liquids in earlier works.…”

Antioxidant behavior and tribological performance of a novel multifunctional additive in complex lithium grease

“…Therefore, lubricants are fairly straightforward to be contaminated, oxidized and even invalidated as a result of their interaction with the friction pairs under various extreme conditions (Bakunin et al , 2004; Ju et al , 2020; Usman, 2020). To resolve those problems, it is indispensable to introduce lubricant additives into the lubricating systems to guarantee the stable performance of lubricants (Ye et al , 2020; Jiang et al , 2020; Zhan et al , 2019; Wang et al , 2019).…”