Dorgham, A, Azam, A orcid.org/0000-0002-3510-1333, Parsaeian, P orcid.org/0000-0001-8393-3540 et al. (5 more authors) (2021) Understanding the effect of water on the transient decomposition of zinc dialkyldithiophosphate (ZDDP). Tribology International, 157. 106855. ISSN 0301-679X
Abstract
The effect of water on the transient kinetics of the decomposition reaction of zinc dialkyldithiophosphate (ZDDP) additive has been investigated using X-ray photoelectron spectroscopy (XPS). Water was found to have a long-lasting detrimental effect on ZDDP triboreactive film layers by changing their composition depending on their proximity to the metal surface. Particularly, water impeded the polymerisation reaction in the top layers, which results in the formation of short zinc (thio)phosphate chains. The most probable explanation for this was related to the formation of a single or multiple bridges between water molecules and PO2 groups of the decomposed ZDDP. This caging effect, which does not fade away as water evaporates, can suppress the chemical reactivity of these groups to a great extent, which in turn can hinder their polymerisation into long phosphate chains.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Tribology International. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | ZDDP antiwear; Tribofilm; Decomposition reactions; XPS; Water contamination |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Functional Surfaces (Leeds) |
Funding Information: | Funder Grant number EPSRC (Engineering and Physical Sciences Research Council) EP/R001766/1 EPSRC (Engineering and Physical Sciences Research Council) EP/R00496X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Jul 2021 15:25 |
Last Modified: | 19 Jan 2022 01:38 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.triboint.2021.106855 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:176137 |