General climate changes and catastrophic environmental pollution cause the steadily increasing interest in the world to bio-based technical oils, including lubricants. In order that they bully comply with current environmental requirements, the additives added to them must not contain environmentally harmful components and provide the maximum thermal oxidation stability of the base oil. A significant disadvantage of zinc dialkyl dithiocarbamates and dialkyl dithiophosphates, which are widely used today as highly efficient polyfunctional additives, is that they contain ecotoxic organosulfur and organophosphorus components. In view of this, complexes of biometals with hydroxamic acids are promising. The paper presents the results of a study of the influence of MoO2L2, ZnL2, CuL2, MgL2 coordination compounds with N-methyldecanohydroxamic acid (HL) and mixtures of MoO2L2 with tert-butylcatechol and 2,6-di-tert-butyl-4-methylphenol (ionol) on the oxidation of distilled sunflower fatty acid methyl esters (one of the variants of biodiesel). Procedures for the synthesis of novel homoleptic Mg(II) and Zn(II) bis-hydroxamate complexes and their spectral characteristics are presented. The antioxidation properties of the complexes contained in the model solutions were determined by the method of oxygen absorption in a hermetically sealed system at 110 C. It has been found that the magnesium complex has no effect on the oxidation of the substrate, and that the copper complex decomposes, under experimental conditions, to metallic copper, which is an oxidation promoter. Zinc and molybdenum complexes exhibit antioxidation properties. It has been shown that ionol is an efficient co-component for MoO2L2, but no synergistic effect was detected. In view of the high tribological characteristics, the MoO2L2 complex is a promising prototype for the development of a polyfunctional eco-friendly additive to commercial biodisel-based lubricating compositions.
Fox N.J., Stachowiak G.W. Vegetable oil-based lubricants - A review of oxidation. Tribology International. 2007. 40. 1035–1046.
Knothe G., Van Gerpen J.H., Krahl J. The Biodiesel Handbook. AOCS Press, Champaign. Illinois. 2005. 286.
Klamann D. Lubricants and Related Products. Synthesis, Properties, Applications, International Standards. Khimiia. Moscow. 1988. 487. [In Russian].
Ukraine 2050 green energy transition concept. Official portal of the Ministry of Environmental Protection and Natural Resources of Ukraine. URL: https://mepr.gov.ua/news/34424.html (date of document review: 26.05.2021).
Geletukha G.G., Zheliezna T.A., Kucheruk P.P., Oliinyk Ye. N., Tryboi O.V. Bioenergy in Ukraine: State of the Art and Prospects for Development. Part 1. Industrial Hheat Engineering. 2015. 37 (2). 68-76. [In Russian].
Коvtun G.A., Моiseev I.I. Complexes of transition metals in catalysis termination oxidation chains. Russian Journ. of Coord. Chem. 1983. 9. 1155–1181. [In Russian].
Kovtun G.A., Sukhoveev V.V. Antiwear properties of complexes of metals: connection of structure with efficiency. Ukrainian Chemical Journal. 2000. 66(9). 22–27. [In Ukrainian].
Frolov V.I. Stereochemical aspects of the antioxidant action of metal complexes from Mannich phenolic bases. Proceedings of Gubkin Russian State University of Oil and Gas. 2009. 2. 144–165. [In Russian].
Bozhko Ye.О., Каchkоvsky О.D., Kalashnikova L.E., Hodyna D.M., Kamenieva T.M., Sheludko Ye.V., Polunkin Ye.V. Initiated oxidation of benzyl alcohol and cyclohexylamine in the presence of Me-complexes. Кіnetics and quantum-chemical modeling. Catalysis and Petrochemistry. 2018. N27. 25-33. [In Ukrainian].
Sukhoveev V.V., Kovtun G.A. Metalcomplexes on the basis of sulfolene-3 derivatives: antioxidative ability. Catalysis and Petrochemistry. 2001. N8. 1-10. [In Ukrainian].
Sharma B.K., Perez J. M., Erhan S.Z. Soybean oil-based lubricants: A search for synergistic antioxidants. Energy & Fuels. 2007. 21. 2408-2414.
Nicholls M. A., Than Do, Norton P.R., Kasrai M., Bancroft G.M. Review of the lubrication of metallic surfaces by zinc dialkyl-dithiophosphates. Tribology International. 2005. 38. 15-39.
Engineering and Design Lubricants and Hydraulic Fluids (EM 1110-2-1424). Publ. U.S. Army Corps of Engineers (USACE), Washington, DC 20314-1000, 1999. 198. https://www.cedengineering. com/userfiles/Lubricants%20and%20Hydraulic%20Fluids.pdf.
Morina A., Liskiewicz T., Neville A. Designing new lubricant additives using biomimetic. WIT Transactions on Ecology and the Environment. 2006. 87. 157–166.
Green E.S.R., Evans H., Rice-Evans P., Davies M.J., Salah N., Rice-Evans C. The efficacy of mono hydroxamates as free radical scavenging agents compared with di- and trihydroxamates. Biochemical Pharmacology. 1993. 45 (2). 357–366.
Patent RU 2034909. Russian Federation. Alekseev N.M., Kuzmyn N.N., Shuvalova E.A., Pavlov I.V., Lutsekovych L.T., Muraveva T.I., Sarkysiants N.R., Ternovaia T.V., Myroniuk H.Y. Grease grease. 1995. [In Russian].
Koval L.I., Dzyuba V.I., Ilnitska O.L., Pekhnyo V.I., Mishchuk O.A. Coordination compounds of life metals and bioligands as model additives to ecofriendly lubricating compositions. Chemistry, Physics and Ttechnology of Surface. 2015. 6 (1). 147-164. [In Ukrainian].
Mishchuk O.A., Koval L.I., Dzyuba V.I., Pekhnyo V.I. Peculiarities of bis-chelate complexes of magnesium(II) as ecologically safe and highly effective lubricating additives of new generation in aspects of tribochemistry of steel surface. Reports of the National Academy of Sciences of Ukraine. 2020. 6. 83-91. [In Ukrainian].
Dzyuba V.I., Koval L.I., Bon V.V., Pekhnyo V.I. Synthesis and structure of lipophilic dioxo-molybdenum(VI) bis(hydroxamato) complexes. Polyhedron. 2010. 29. 2900–2906.
Dzyuba V.I., Koval L.I., Shtokvysh O.O., Trachevskii V.V. , Pekhnyo V.I. Lipophilic chloro-oxo-bis(hydroxamato)-vanadium(V) complexes: synthesis methods and structure. Polyhedron. 2020. 180. 114421.
Wakefield B. J. Organolithium Methods. Mir, Moscow. 1991. 184. [In Russian].
Dzyuba V.I., Koval L.I., Pekhnyo V.I. An accessible method for the evaluation of the thermo-oxidative stability of organic substrates based on vegetable oils. Thermochimica Acta. 2016. 632. 91–93.
Koval L.I., Dzyuba V.I., Pekhnyo V.I. Novel method for the evaluation of the activity of antioxidants (procedure and substrate). Catalysis and Petrochemistry. 2015. N24. 65–69. [In Ukrainian].
Jain S., Sharma M.P. Stability of biodiesel and its blends: A review. Renewable and Sustainable Energy Reviews. 2010. 14. 667–678.
Zubenko S.O., Patrylak L.K., Konovalov S.V. Comparison of physicochemical and performance properties of biodiesel fuel based on methanol and bioalcohols. Catalysis and Petrochemistry. 2018. N27. 1-18. [In Ukrainian].