New principles in the study of chemmotology of oils

Abstract

The complexity of the systems studied in chemmotology, together with the need to study them in depth, compels researchers to seek various methods to simplify these systems, i.e., to idealize them to some extent or other. This makes it easier to set up experiments and to analyze the results obtained although sometimes one cannot then correlate these results reliably with the operational data. The reason for this lies, first of all, in the substantial differences between the idealized state of the substance studied and the conditions of its actual operation. In the present article, we have attempted to show the need for and the ways of improving the principles of study in the chemmotology of oils with a view to making such a study more objective and productive and to eliminating the ineffective conventional methods which have been developed during the last few decades. Idealization of systems as a method of study of oils was used widely in the 1950s and 1960s primarily because the instrumental methods were imperfect and because there were no well-developed principles for analyzing the results. Unfortunately, the current level of some studies in chemmotology, including generalization of results and development of hypotheses, do not differ much from the level 20-30 years ago. This situation is due to the unsatisfactory standard of theoretical work, so that there is no strict quantitative relationship between the parameters evaluated, which characterize the operational properties of oils, and the reliability of the item lubricated. This reduces the objectivity and the information content of the results obtained in the various stages of studies and experiments, especially in the stages of synthesis of the functional additives and development of high-efficiency oil compositions. Thus, the lack of clearly formulated requirements which can be quantitatively interpreted makes it impossible to relate the composition and structure of a chemical compound with the efficiency of its function, rules out or limits the possibility of directed synthesis and optimization of the structures of the compounds synthesized. Therefore, during studies, one has to follow predominantly qualitative criteria that relate the efficiency of a compound to the presence of certain active elements in its molecule. In particular, in antiwear additives, sulfur, phosphorus, or their combinations act as such elements. However, changes in the mobility of their molecules as a function of the strength of the solvent (disperse medium) the presence of other surface-active substances in the solution and other important factors are usually ignored. Since there are no strict theoretical or basically developed principles, it is not possible to improve the methodology of additive selection and development of optimal oil compositions. This makes it necessary to carry out a large number of experiments, including comprehensive evaluation in the laboratory, test-bench, and operational conditions. However, for the above-mentioned reasons the results obtained are not sufficiently reliable and objective. For example, a common method for evaluation of the antioxidant efficiency of additives and the antioxidant properties of oils is to vary the temperature, pressure, and weight of