Unique synergism between zinc dialkyldithiophosphates and Schiff base bridged phenolic diphenylamine antioxidants. (May 2020)

• Record Type: Journal Article
• Authors: Wang, Shengpei; Yu, Shasha; Huang, Bo; Feng, Jianxiang; Liu, Shenggao
• Is Part Of: Tribology international. Volume 145(2020)
• Publication Date: 2020-05
• Subjects: Antioxidant -- Antiwear -- Schiff base -- ZDDP; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2019.106134
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: The effects of four Schiff base bridged phenolic diphenylamine antioxidants (SSPDs) on the multifunctional properties of a traditional additive zinc dialkyldithiophosphate (ZDDP) were studied. Interestingly, it is observed that the cooperation between SSPDs and ZDDP improves the antioxidant, antiwear and extreme pressure of lubricant oil, but does not reduce its anticorrosive property. The EDS and XPS results indicated that a unique interaction was occurred between SSPDs and ZDDP. In addition, the synergistic effect was studied by NMR, which showed that SSPD selectively disintegrated the cage structures (basic form) of the ZDDP to afford a donor-acceptor complex via the coordination of nitrogen of imine to the zinc atom. Highlights: Schiff base bridged phenolic diphenylamine (SSPDs) antioxidants were studied. Interestingly, SSPDs improve antioxidant, antiwear and extreme pressure of ZDDP. The distinct synergism between SSPDs antioxidants and ZDDP was discovered. The unique interaction between SSPDs and ZDDP was studied by SEM-EDS, XPS and NMR.