New Method for the Study of the Oxidation Stability and Corrosiveness of Lubricating Oils
Abstract
The new method of analysis of oils for the presence of polar compounds has been described in NRL Reports Nos. P-1595, P-1621, and P-1640. Because the spreading oil drop method is very sensitive to the presence of organic oils, is rapid in operation, and requires only one drop of oil for a test, it is especially well suited for the testing of the heat light, and oxidation stabilities of oils. This is the first report on results obtained by this method on the oxidation stability of typical lubricating oils, two highly refined white oils, and Dupont Cetane, the standard for rating diesel fuels. It was found that the earliest products of the oxidation of the oil are volatile compounds. These were found to be low molecular weight polar molecules such as ketones, alcohols and acids. Later in the course of the oxidation process, higher molecular weight non-volatile polar compounds are formed. The time of commencement of the production of these compounds is sharply defined and is shown to be the same as the "induction period" or "induction time" so familiar in oil and gas analysis. From then on, the amount of high molecular weight compounds produced increases with great rapidity. In fact, a graph of the logarithm of the total amount of high molecular weight polar compounds vs. the time of oxidation is found to be a straight line. When the oxidation has progressed considerably, oil insoluble substances begin to form.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 1942
- Accession Number
- AD1165737
Entities
People
- Charles M. Jr Murphy
- W. Zisman
Organizations
- United States Naval Research Laboratory