Combination of ashless antiwear additives with metallic detergents: interactions with neutral and overbased calcium sulfonates

Najman, M.N.; Kasrai, M.; Bancroft, G.M.; Davidson, R. D.

doi:10.1016/j.triboint.2005.02.014

Cited by 57 publications

(44 citation statements)

References 22 publications

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“…On the contrary (4) wear width; (5) wear volume detergent and other additives in fully formulated oil played a competing role in reducing the resistance of the tribofilm. This was explained by Najman et al (2006). XPS and EDX revealed that when oil is blended with calcium sulfonate, considerable amount of calcium is incorporated into the tribochemical films.…”

Section: Tribological Wear Data For Fluorinated Plain Zddp Oil Samplesmentioning

confidence: 92%

Fluorinated interactions in two different plain ZDDP oils using design of experiment (DOE) and chemistry characterization of tribofilms

Nehme

2012

Industrial Lubrication and Tribology

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Purpose -The purpose of this paper is to study the friction and wear performance of two plain ZDDP oils in the presence of fluorinated catalyst and PTFE combinations under extreme boundary lubrication of 385 Newton load (Hertzian contact pressure of 2.72 GPa). The mechanism of tribofilm formation and breakdown was followed carefully by monitoring the friction coefficient over the duration of the test. Design/methodology/approach -Very reproducible boundary lubrication tests were conducted as part of design of experiment (DOE) to study the behavior of two different fluorinated plain oils in developing environmentally friendly (reduced P atd S) anti-wear additives for future engine oil formulations. Friction and wear performance of ZDDP plain oils improve in the presence of fluorinated mix combinations. In order to understand the wear mechanism, different factors of chemical compositions and different wear responses were analyzed and optimized using DOE. Several chemistry combinations were prepared and tested under extreme boundary lubrication. Findings -The interactions of fluorinated mix with minimum phosphorus were studied and compared. Tribofilms with thickness ranging from 300-400 nm were developed during wear tests and were analyzed for two fluorinated plain oils that target reducing phosphorus. Originality/value -The influence of catalyst and PTFE fluorinated mix were examined. Scanning electron microscopy with chemistry analysis was developed. Hardness of the tribofilms, X-ray of the wear track and Auger spectroscopy confirm the present of fluorine and phosphorus. The two repeated tests that were conducted on both plain oils with minimum fluorinated mix confirm the prediction of the DOE model.

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Section: Tribological Wear Data For Fluorinated Plain Zddp Oil Samplesmentioning

confidence: 92%

Fluorinated interactions in two different plain ZDDP oils using design of experiment (DOE) and chemistry characterization of tribofilms

Nehme

2012

Industrial Lubrication and Tribology

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“…Recently, calcium sulfonates have been explored for their antiwear (AW) properties. These detergents keep the metal surfaces of an engine clean, also possess desirable AW, anti-scuffing properties [11][12][13][14]; overbased detergents are also known to play a significant role as antiwear, extreme pressure, and friction-reducing additives. Basically, these additives are colloidal dispersions of metal hydroxides, carbonates, or borates stabilized by metallic soaps such as phenates, salicylates, or sulfonates.…”

Section: Introductionmentioning

confidence: 99%

Preparation and evaluation of the mixtures of sulfonate and phenate as lube oil additives

et al. 2017

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Lubricating oil additives impart new properties to oil or reinforce desirable properties already possessed by the oil. They are used to prevent sludge and varnish deposits in engines, to inhibit rust and corrosion, and to minimize wear and friction. Detergents, especially basic detergents, contain reserve base that will neutralize the acids, while this decreases the corrosive tendency of the acids formed at high temperatures. Dispersants also disperse sludge formed in engine operated at low temperature. In the present work, neutral, basic, and overbasic calcium salt of sulfurized dodecyl phenol and neutral calcium sulfonate were prepared and evaluated as antioxidant and detergent/dispersants. Also, different metallic mixtures were prepared via mixing dodecyl benzene sulfonic acid and neutral calcium salt of dodecyl phenol in different ratios. Then basic and overbasic of corresponding mixtures were prepared using excess of calcium hydroxide and carbon dioxide. The efficiency of the prepared compounds as detergent/dispersant additives for lubricating oil was investigated. It was found that the prepared additives have excellent power of dispersion and detergency and this efficiency increases by increasing basicity, percentage of calcium salt, and the ratio of dodecyl benzene sulfonic acid in the mixture.

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“…metal-free) additives, such as organosulfur compounds [6], phosphates [6][7][8][9][10][11][12][13][14][15][16], amine phosphates [12], phosphites [11,[17][18][19], phosphorothionates [12][13][14][20][21][22][23][24][25][26], and dithiophosphates [12,21,22,24].…”

Section: Introductionmentioning

confidence: 99%

“…Several analytical techniques have been employed to characterize the reaction layers, such as X-ray photoelectron spectroscopy (XPS) [7,12,14,25,26], X-ray absorption spectroscopy (XAS) [13,[21][22][23][24], X-ray photoelectron emission microscopy (X-PEEM) [24], scanning electron microscopy (SEM) [20,21], Fourier transform infrared spectroscopy (FT-IR) [7,14,16], Auger electron spectroscopy (AES) [8-10, 14, 17, 18], and atomic force microscopy (AFM) [22]. Najman et al investigated the thermal films and tribofilms formed by phenyl phosphates on steel [13].…”

Section: Introductionmentioning

confidence: 99%

Reactivity of Triphenyl Phosphorothionate in Lubricant Oil Solution

2009

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Investigating the thermo-oxidative reactivity of anti-wear additives in lubricant oil solution at high temperature can significantly contribute to an understanding of the mechanism of thermal film and tribofilm formation on metal surfaces. In this study, the reactivity of triphenyl phosphorothionate (TPPT) in lubricant oil solution at high temperature (423 and 473 K) has been studied by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. The results show that the TPPT molecule was highly thermally stable and did not completely decompose in oil solution even upon heating at 423 K for 168 h and at 473 K for 72 h. The degradation of the TPPT molecule, which turned out to be a first-order reaction, started taking place after 6 h at both temperatures, leading to the breakage of the P=S bond with the formation of triphenyl phosphate. During these heating experiments, no oil-insoluble compounds were detected. The oxidation of the base oil as a result of the prolonged heating demonstrated that the TPPT molecule did not effectively act as oxidation inhibitor.

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Combination of ashless antiwear additives with metallic detergents: interactions with neutral and overbased calcium sulfonates

Cited by 57 publications

References 22 publications

Fluorinated interactions in two different plain ZDDP oils using design of experiment (DOE) and chemistry characterization of tribofilms

Fluorinated interactions in two different plain ZDDP oils using design of experiment (DOE) and chemistry characterization of tribofilms

Preparation and evaluation of the mixtures of sulfonate and phenate as lube oil additives

Reactivity of Triphenyl Phosphorothionate in Lubricant Oil Solution

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