Hindered Phenol Derivative as a Multifunctional Additive in Lithium Complex Grease

Abstract

This paper describes 3-(3,5-di-tert-butyl-4-hydroxy-phenyl)-propionic acid 2-(4-meth yl-thiazol-5-yl)-ethyl ester (BHMT) as a high-performance multifunctional additive in lithium complex grease (LCG). The tribological properties and antioxidant behaviors of BHMT were evaluated by tribological test and thermal analysis respectively, and compared with those of zinc dialkyldithiophosphate (ZDDP). The tribochemical film BHMT generated on the worn surface was analyzed by X-ray photoelectron spectroscopy (XPS). Tribological results indicated that BHMT exhibited better friction-reduction and antiwear properties than ZDDP. The thermal analysis demonstrated that the anti-oxidation ability of BHMT was superior to that of ZDDP.Moreover, XPS results showed that lubrication film composed of iron oxide, iron sulfate and nitrogen oxide was formed on the worn surface, which was an explicit explanation of the tribochemical mechanism of BHMT.

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

“…Pressurized differential scanning calorimetry (PDSC) tests were performed using a NETZSCH DSC 204HP instrument (Bavarian, Germany) according to ASTM D 6186-08(2013). The detailed experimental conditions are described in a previous study [23]. The oxidation onset temperature (OOT) was obtained via temperature programmed experiments and a higher OOT indicates better oxidation stability of the lubricant.…”

Synthesis and Evaluation of 4-Hydroxy Quinolinone Derivatives as Antioxidants of Lubricating Grease

“…2-hydrazono-5-((4-hydroxy-8-methyl-2-oxo-1,2-dihydroquinolin-3yl) methylene)-1-phenyldihydropyrimidine-4,6(1H.5H)-dione (II). It was prepared by a mixture of pyrimidinethione (0.01 mol) and hydrazine hydrate (0.01 mol) in absolute ethanol (20 cm 3 ) and then the mixture was refluxed for 4 h. The solid product that obtained was filtered off and crystallized from DMF: (Scheme 2). Using the same method as for preparation of 1, 4, we used cinnamaldehyde with the some acetyl instead of thiophene-2-carboxaldehyde to produce III.…”

“…Most phenolic antioxidants used in lubricating greases are phenolic derivatives having a tertiary butyl group. Recently, bearings have been increasingly used in applications where high temperature environments are present [3]. El-Adly et al [4] prepared some azine and azole derivatives and they were evaluated as antioxidant additives for lithium lubricating grease.…”

Multifunctional lubricant additive based on difluoroboron derivatives of a diphenylamine antioxidant

“…6 Therefore, it is a progressive trend to develop new non-SAPS or low SAPS multifunctional lubricant additives without reducing the antioxidation and antiwear capabilities. [7][8][9] Several kinds of compounds with low or zero SAPS has been studied, such as heterocyclic compounds, [10][11][12] boron containing compounds, [13][14][15] ionic liquids 16,17 and nanoparticles. [18][19][20] It is well known that antioxidants can improve the oxidation stability of lubricant.…”

“…Modication of antioxidants with the active elements of B, S and P is a research hotspot of multifunctional lubricant additives, such as multifunctional Schiff bases (e.g. CySBE and TrBzEd), [21][22][23][24] high performance multifunctional additive BHMT, 10 N-containing borate ester BMEB (ref. 25) and imidazolium-based ionic liquids (e.g.…”