Fatty Acids Chemical Specialties

FATTY ACIDS FOR CHEMICAL SPECIALTIES A symposium of the Soap, Detergents and Sanitary Chemical Products Division of the Chemical Specialties Manufacturers Association FATTY ACID SYMPOSIUM Soaps, Detergents and Sanitary Chemical Products Division of the CSMA Moderator: DR. D. H. TERRY The Bon Ami Company New York, New York OPENING REMARKS sion of the Soap Association, and other members of the Soap Association for their excellent cooperation and assistance in Mr. Chairman, Ladies and Gentlemen, the subject to be arranging this panel discussion. discussed this morning is "Fatty Acids." The topics to be discussed by the panel members were For many, many years Fatty Acids have been the main selected so that fatty acids would be covered completely from ingredients in the production of all types of soaps. The soap their basic chemistry to their end uses in special products. industry is one of the oldest in America, and has been and continues to be a very important economic factor in our The panel members were selected from the major producers everyday living. P of fatty acids and chemical specialties. They are all experts in this field. The uses of soap have become innumerable and varied. Its largest market is in the home, where its chief uses are I would now like, to introduce the panel members. First, as toilet soap and as laundry soap. There are, however, very Dr. H. C. Black of Swift and Company, who will speak on many industrial applications for soap because of its wetting, the "Basic Chemistry of Fatty Acids"; Dr. H. Wittcoff of emulsifying and cleansing powers. Soap is nqw found in many General Mills, Incorporated who will discuss the "Properties commercial processes. of Fatty Acids and Analytical Methods"; Dr. M. R. McCorkle of Armour and Company, who will cover "Reaction Products Over the past five years soap requirements, sales, and of Fatty Acids"; Dr. George Zinzalian of E. F. Drew and production have slowly decreased. This has also reflected a Company who will speak on "Storage and Handling of Fatty decreasing requirement for fatty acids, since they are the Acids"; Mr. R. D. Aylesworth of Emery Industries, Incor- basic ingredient in soap production. porated whose subject will be "Requirements of Fatty Acids In view of this decline in the requirements for fatty acids, used in Liquid and Metallic Soaps"; and Dr. H. Lederer of many companies have spent considerable time and effort in R. M. Hollingshead Corporation who will conclude the formal research and market development to develop new outlets, presentation part of this program with a paper on "Re- uses and applications for fatty acids. In this investigation quirements of Fatty Acids used in Other Chemical Specialty many new and interesting developments have been uncovered Products." in regard to fatty acids. In order to keep the meeting running without any inter- Approximately five years ago this division sponsored a ruption, the six speakers will give their papers in the order symposium on fatty acids. In view of the more recent develop- introduced. After the last paper has been completed, there ments on fatty acids, it was felt worthwhile to have another will be a short recess during which we will collect the forms panel discussion on these materials. which were handed to you as you came in. Please write any The purpose of this symposium, organized through the questions you wish to ask, the name of the panel member combined efforts of the Market Development Committee of to whom you want it directed, and your name and company. the Fatty Acid Division of the Soap Association, and the If you do not direct it to any one person, then we will try to Soaps, Detergents and Sanitary Chemicals Division, is to dispose of it as best we can. I also want to suggest that there convey to the members of the CSMA all the latest informa- is no rule in this panel against panel members' asking each tion available on fatty acids. other questions. We wish to thank Mr. Scott Pattison, Manager of the Now I would like to proceed with the more interesting Fatty Acid Division of the Soap Association, Mr. B. W. part of the program by introducing the first speaker at Schroeder, Chairman CSMA Sub-committee, Fatty Acid Divi- this time. BASIC CHEMISTRY OF FATTY ACIDS by H. C. BLACK Associate Director of Research Swift & Co., Chicago, 111. INTRODUCTION we have had recently. In the past two decades, much work has been done and. many articles and numerous good books The basic structure of fats was established nearly a century on fats and fatty acids have been published. We know the and one-half ago when Chevreul found that they were -com- structure of the great majority of the known fatty acids posed of fatty acids and glycerol. A little later Gusserow and have information as to how to prepare and make prac- separated saturated from unsaturated acids by differential tical use of many of their derivatives in our expanding solubilities of their lead salts. Even though many significant chemical era. and ,brilliant discoveries were made during the nineteenth SOURCES century, the fats and fatty acids were sadly neglected until the beginning of the twentieth century. They were not attrac- Fats are essential constituents of all forms of plant and tive research materials because they were not readily crystal- animal life, and are consequently widely distributed. However, lizable and few crystalline derivatives could be prepared. In the plants and animals that produce oils and fats in snffi- spite of the lack of basic chemical knowledge during the cient quantity to constitute a significant source are few. The nineteenth century, much empirical information. accumulated largest of these comprises the annual plants sucli as flax, permitting establishment of the consuming industries such soybean, cotton, peanut and castor bean. These grow in as food, soap, paints and varnishes. There was no surplus as temperate climates requiring cultivation. Production can be varied. The second source of vegetable oils is the oil bearing UNSATURATED ACIDS trees such as coconut, palm, olive, and tung. These grow in the warm or temperate climates. These acids, particularly the highly unsaturated members, are not as well characterized as the saturated acids because The commercial land animal fats come largely from hogs, of the difficulties in isolating them. Also, changes can occur sheep and cattle. Milk fats are nearly all used for food. The during separation and identification. sea contributes a considerable volume of oil. Among the most important sources are sardine, menhaden, herring and whale, The unsaturated acids differ from one another in the including sperm whale. number of carbon atoms, the number of double bonds, the position of the double bonds, and the geometry of the double bonds. All of the unsaturated acids, with the exception of CHEMISTRY elaidic, are liquid at room temperature. Fatty acids are present in fats and oils as glycerides or esters of glycerol except in sperm oil, where some of the TABLE I1 fatty acids are esterified with fatty alcohols, mainly cetyl alcohol. The fatty acids are released by hydrolyzing ester Unsaturated Acids linkage. This is done by chemically adding water, a process (Monoethylenic) commonly referred to as fat splitting. The most common methods are the Twitchell, autoclave, and continuous methods. Number of In the Twitchell process a catalyst speeds up the reaction Common Name Carbon Atoms Geneva Name as the fat is heated with boiling water. The autoclave method depends on heat to speed the reaction. The continuous method Obtusilic ........................ 10 ...................... 9 :10 Decenoic also relies on heat, and is carried out by passing water and Caproleic ....................... 10 ...................... 4:5 Decenoic fat countercurrently through a tower. Lauroleic...................... 12 ...................... 9:10 Dodecenoic The fatty acids resulting from the splitting operation can 12 ...................... 4:5 Dodecenoic be used as such or further processed to-remove non-fatty Myristoleic 14 9 :10 Tetradecenoic acid constituents, and fractionated by distillation or selective ................... ...................... solvent extraction. They may be fractionally crystallized by 14 ...................... 4:5 ~etradecenoic chilling and pressing, or by the use of solvents. New tech- 14 ...................... 5 :6 Tetradecenoic niques still in the experimental stage for separation are Palmitoleic.................... 16 ...................... 9 :10 Hexadecenoic molecular diffusion and the use of urea or thiourea to form Oleic............................... 18 ...................... 9 :10 Octadecenoic complexes. Petroseleric.................. 18 ...................... 6 :7 Octadecenoic FATTY ACIDS Elaidic ........................... 18 ............ trans 9 :10 Octadecenoic Vaccenic ........................ 18 ............trans -11:12 Octadecenoic The natural fatty acids are generally aliphatic compounds with a carboxyl group at the end of a straight carbon chain. Gadoleic: ........................ 20 ...................... 9 :10 Eicosenoie Nearly all of them have an even number of carbon atoms. Erucic............................ 22 ...................... 13 :14 Docosenoic The acids differ from one another in the number of carbon atoms and the number and position of the double or unsa- turaljed bonds. Table I1 shows the common fatty acids with one double SATURATED ACIDS bond. When one double bond exists,' it can be between any two of the carbons except the first and second. However, The saturated acids contain no double bonds. They vary only a few of the possible positions are found in nature. in chain length from butyric, which contains four carbon In addition, at any double bond, it is possible to have two atoms, to lignoceric, which has 24. Table I shows the common geometric isomers referred to as cis-trans isomers. Table saturated acids. At room temperature the shorter chain length I11 represents this. Oleic acid is cis, and elaidic acid is trans. acids are liquid. Lauric and all longer chain acids are solids at room temperature. The most widely distributed and the most commercially important are palmitic and stearic acids.

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