Results 131 to 140 of about 314 (176)

The antiwear mechanism of zddp's. Part I

Tribology International, 1982
Abstract Zinc dialkyldithiophosphates (zddp's) have been used in internal combustion engine oils for over 30 years as antiwear and antioxidant additives. In this paper, their mode of action is investigated. It was concluded, using various analytical techniques, that zddp's decompose in oil solution predominantly by a hydrolytic mechanism, ultimately ...
H. Spedding, R.C. Watkins
exaly   +2 more sources

Tribochemistry of ZDDP in molecular orbital calculations

Tribology International, 2004
Abstract The molecular orbital parameters of zinc dialkyldithiophosphate (ZDDP) and several metal-atom-cluster models were calculated. The nature and the strength of the interactions between the ZDDP molecules and different metal surfaces are analysed and discussed with the use of frontier orbital theory.
Xueye Wang, Yuanqiang Tan, Weijiu Huang   +2 more
exaly   +2 more sources

Antiwear Behavior of ZDDP and Fluorinated ZDDP in the Presence of Alkylated Diphenyl Amine Antioxidants

Tribology Transactions, 2008
Environmental regulations have called for a reduction of phosphorus content in engine oils in recent years. The anti-wear additive zinc dialkyl dithiophosphate (ZDDP), which is also an antioxidant, is one of the most important components of engine oil additives. ZDDP is a major source of phosphorus.
A. Somayaji, P. B. Aswath
openaire   +1 more source

The origin of anti-wear chemistry of ZDDP

Faraday Discussions, 2012
Molecular Dynamics has been used to simulate the anti-wear chemistry of zinc dialkyl dithiophosphate (ZDDP). The model simulates the digestion of abrasive particles into the zinc polyphosphate glass. The main result is that the driving force for the tribochemical reaction is not temperature but entropy due to mechanical mixing at the atomic scale.
Jean Michel, Martin, Tasuku, Onodera, Clotilde, Minfray, Fabrice, Dassenoy, Akira, Miyamoto   +4 more
openaire   +2 more sources

Synthesis of Fluorinated ZDDP Compounds

Part A: Tribomaterials; Lubricants and Additives; Elastohydrodynamic Lubrication; Hydrodynamic Lubrication and Fluid Film Bearings; Rolling Element Bearings; Engine Tribology; Machine Components Tribology; Contact Mechanics, 2006
Volatile degradation products of zinc dialkyl dithio phosphate (ZDDP) composed of phosphorus and sulfur compounds reduce the efficiency of catalytic converters resulting in harmful emissions. A unique way of reducing ZDDP level while maintaining good antiwear performance has been achieved by reacting a novel additive FeF3 with ZDDP.
K. Parekh, P. B. Aswath
openaire   +1 more source

Effects of Temperature and Pressure on ZDDP

Tribology Letters, 2007
A recent theoretical study proposed that the anti-wear property of zinc dialkyl dithio phosphate (ZDDP) is due to the formation of chemically connected networks as a result of pressure-induced cross-linkage of phosphate groups of thermally decomposed ZDDP.
John S. Tse, Yang Song, Zhenxian Liu
openaire   +1 more source

Antiwear Chemistry in Presence of ZDDP

World Tribology Congress III, Volume 1, 2005
Antiwear chemistry is related to the role of tribochemical reactions in controlling abrasive wear, adhesive wear as well as physical and mechanical properties of tribofilms. In the case of additives in boundary lubrication, three different chemical reactions have been found to be directly connected to mechanical response.
J. M. Martin, C. Minfray
openaire   +1 more source

Nanoscale Mechanical Properties of In-Situ Tribofilms Generated from ZDDP and F-ZDDP with and without Antioxidants

Journal of Nanoscience and Nanotechnology, 2007
Tribofilms with thickness ranging from 100–200 nm were developed in-situ during wear tests using a zinc dialkyl dithiophosphates (ZDDP) and fluorinated ZDDP (F-ZDDP). The influence of the antioxidant alkylated diphenyl amine on the formation and properties of these tribofilm is examined.
Anuradha, Somayaji, Ramoun, Mourhatch, Pranesh B, Aswath   +2 more
openaire   +2 more sources

Polymer esters and their synergy with ZDDP – the possibility of reducing ZDDP content in lubricants

Journal of Synthetic Lubrication, 1995
AbstractIn recent years, environmental awareness and legislation have enforced ever greater controls on the emissions of motor vehicles. To meet those requirements, the increased use of exhaust port catalysts is almost inevitable. However, there are concerns that lubricant‐derived phosphorus compounds could in the long term be detrimental to those ...
openaire   +1 more source

Tribochemistry of ZDDP and MoDDP chemisorbed films

Tribology Letters, 1996
By means of a UHV analytical AES/XPS pin-on-flat tribotester, we have investigated tribochemical change as well as transfer mechanisms in static reaction films on steel from ZDDP (anti-wear) and MoDDP (friction modifier) lubricant additives. The results show that solid ZDDP reaction films are able to strongly reduce friction to a value of 0.1–0.3 (in ...
J. M. Martin, Th. Le Mogne, C. Grossiord, Th. Palermo   +3 more
openaire   +1 more source