"It has been known for many years that certain metallic soaps catalyse the drying of oils. A great deal of information is available concerning the use of these soaps, but there is little knowledge of the actual manner in which the soaps catalyse drying. As the drying is known to be an autoxidation reaction, it is generally believed that the soaps must affect the oxidation of the oil in some way. The work described in this thesis was undertaken to gain some knowledge of the mechanism of the catalysis, and to correlate the effect of the soaps on the drying reaction with the electronic structure of the metals involved.
A review of the literature concerning drying oils and driers (the common term used to describe the metallic soaps mentioned above) shows many inconsistencies in data concerning the effect of driers on the autoxidation of oils. Much of this inconsistency may be attributed to the difficulties encountered in studying the reaction. Some of these difficulties are:
- The composition of drying oils from different sources may vary. Therefore, the oils may behave differently during oxidation.
- The composition, purity, and quantities used of the soaps influence their effect on the reaction.
- The conditions under which the reaction is carried out affect the course of the reaction.
For these reasons, it is difficult to correlate data from one worker with that from another. In addition, much of the published work in this field has been incomplete. In many cases only a few soaps were studied. In others the products of the reaction were only partially investigated.
The aim of this work was to avoid as many of the above sources of error as possible. The oxidation was performed on linoleic acid instead of a natural drying oil. Linoleic acid was oxidized in the presence of several metallic soaps. An apparatus was assembled which permitted temperature, oxygen pressure and oxygen flow to be held constant during the oxidation. Soaps of a uniform composition were used. These soaps were of the metals of the first transition series with the exception of scandium and titanium. Thus, almost all the possible electron structures of that series were included. The course of the reaction was followed by collecting and analysing samples of the product at frequent intervals. Additional analyses were run on the final product of oxidation.
In addition, the effect of the soaps on the drying time of refined linseed oil was measured. By comparing the results of these measurements and the results of chemical analysis of oxidation products of linoleic acid, it was possible to suggest a mechanism for the drying. Finally, by comparing the effect of the soaps on drying time and on the course of the reaction, it was possible to suggest a mechanism for the catalysis"--Introduction, pages 1-3.
James, William Joseph
M.S. in Chemistry
Missouri School of Mines and Metallurgy
v, 91 pages
© 1956 David Elliott Troutner, All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Linoleic acid -- Oxidation -- Analysis
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Link to Catalog Record
Troutner, David Elliott, "The effect of metallic naphthenates on the oxidation of linoleic acid" (1956). Masters Theses. 2578.