The Preparation of Pure Fatty Acids and the Determination of Their Solubilities at Low Temperatures

John Mandak, Marquette University


The pure fatty acids have been prepared in recent years by a combination ester fractionation and crystallization from suitable solvents. With large amounts of these materials available, it was possible to begin a series of studies on the physical behavior of the acids and their derivatives. This was necessary since work by some previous workers was of a dubious value. Solubility measurements, especially at low temperatures, had been neglected because of lack of facilities for this type of work. Revived interest in solubilities at low temperatures is mainly due to procedures for the separation of saturated from unsaturated acids and due to procedures for the preparation of oleic acid, methyl oleate, and the esters of other unsaturated acids. The above mentioned procedures have been retarded somewhat by a lack of data concerning the solubilities of the higher acids, C10-C18, in various solvents at temperatures below zero degrees centigrade. The present research is concerned with the preparation of several saturated acids and the consequent determination of their solubilities. It is hoped that later work with the other acids and other solvents along with some actual tests with pure saturated and unsaturated acids may provide a more complete picture of what may be done in this field.