Tribochemistry and the development of AW and EP oil additives — a review

Xue, Qunji; Liu, Weimin

doi:10.1002/ls.3010070107

Cited by 41 publications

(8 citation statements)

References 67 publications

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“…Most of the heterocyclic compounds which have compact structure possess antioxidant, anticorrosion and antiwear properties [6][7][8]. Heterocyclic compounds have been reported as antiwear and extreme pressure additives such as thiadiazoles and benzotriazoles [9][10][11][12][13]. Mohammed et al [14] studied the oxidation stability of local base stock in the presence of two antioxidants.…”

Section: Introductionmentioning

confidence: 99%

Studies On Some Thiazolidinones As Antioxidants For Local Base Oil

et al. 2019

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I N THIS work, 5 thiazolidinone derivatives of the type 5-benzylidene -2-(1-piperidinyl)- (105) are synthesized and characterized using conventional tools analyses. They are tested as antioxidants for local base stock and the efficiency of these compounds, as antioxidants, was monitored through studying the change in total acid number and viscosity, the results reveal that the efficiency order is ranked as follows 105 < 104 < 103 <102 < 101. The quantum chemical parameters such as the lowest unoccupied molecular orbital (LUMO), the highest occupied molecular orbital (HOMO) energy levels and the energy gap (E HOMO -E LUMO ) were calculated. The experimental results were on the same line with the quantum chemical calculations.

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Section: Introductionmentioning

confidence: 99%

Studies On Some Thiazolidinones As Antioxidants For Local Base Oil

et al. 2019

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“…This may explain why, despite more than 70 years of extensive research, the mechanisms of film formation and wear protection of the most common and successful class of anti-wear addives, Zinc dialkyldithiophosphates (ZnDTPs), are still incompletely understood [2,3]. ZnDTP is known to react at the steel interface, forming a tribofilm with thickness, chemical and physical properties that are dependent on conditions such as applied load, temperature, and additive concentration [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Effect of Chain-Length and Countersurface on the Tribochemistry of Bulk Zinc Polyphosphate Glasses

2012

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Zinc polyphosphate glasses are considered to be chiefly responsible for the anti-wear efficiency of ZnDTP tribofilms. In this work, the tribochemical properties of amorphous bulk zinc polyphosphates of different chain lengths (ranging from zinc metaphosphate to zinc pyrophosphate) have been investigated. Tribological tests on bulk polyphosphate discs have been carried out using steel and quartz balls as counter-surfaces in a poly-a-olefin (PAO) bath at room temperature. The composition in the wear track and on the contact region of the balls has been monitored by small-area and imaging X-ray photoelectron spectroscopy (i-XPS). The XPS analysis revealed that the composition of short-chain-length polyphosphates remained unchanged following tribological stress. Long-chain-length polyphosphates are depolymerized in the wear track as a consequence of a tribochemical reaction. By comparing the results obtained using quartz and steel balls, it could be observed that while the reaction of iron oxide with the polyphosphates certainly plays a role in the depolymerization of the samples under sliding conditions, pressure and shear stress alone and also in the presence of water or oil-oxidized species are able to depolymerize the glass when an inert material is used as counterpart; the composition of the wear track, in this case, is dependent on the applied load. All samples were able to form an adhesive, glassy transfer film on both steel and quartz balls, but the short-chain-length polyphosphates showed a lower friction coefficient and wear coefficient. The results suggest a third-body mechanism with the polyphosphates acting as a solid lubricant. Differences in tribological behavior of the different-chain-length polyphosphates are attributable to their mechanical and rheological properties.

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“…Figure 5 also shows the depletion of the ZDDP antiwear additive during the field test. Since ZDDP is one of the most extensively used antiwear additives, see [33], [34], and [35], the knowledge about its degradation processes is of great importance, primarily since the tribological properties of lubricants are substantially influenced by the amount of antiwear additives and the presence of its degradation products [36]. ZDDP depletes rapidly during the utilization of the engine oil, depleting completely between 8,000 and 9,500 km.…”

Section: Tribometrical Characterizationmentioning

confidence: 99%

Production of Used Engine Oils with Defined Degree of Degradation in a Large-scale Device

Agocs

Budnyk

Besser

et al. 2020

Acta Tech. Jaurinensis

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Lubricant degradation by additive depletion, contamination and build-up of degradation products deteriorates lubrication performance. It can be expected that engine oil degradation also has an impact on performance parameters. Engine development tends to higher power density, lower engine oil viscosity to optimize fuel efficiency, which heavily stress engine oils and thus demand increased oil performance. Correlations between engine oil degradation, friction and wear during an engine oil’s lifetime are a valuable asset in engine development towards performance, longevity and cost reduction. Here, physical-chemical and tribological properties of engine oils collected from passenger cars were determined. The results revealed the deterioration of friction (loss of fuel efficiency) and wear (increasing loss of material) depending on mileage. Defined used engine oils were produced by artificial alteration in a large-scale device and showed a very good correlation with the field samples.

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Tribochemistry and the development of AW and EP oil additives — a review

Cited by 41 publications

References 67 publications

Studies On Some Thiazolidinones As Antioxidants For Local Base Oil

Studies On Some Thiazolidinones As Antioxidants For Local Base Oil

Effect of Chain-Length and Countersurface on the Tribochemistry of Bulk Zinc Polyphosphate Glasses

Production of Used Engine Oils with Defined Degree of Degradation in a Large-scale Device

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