Noting t h a t in normal t i m e s this count r y produces an excess of fats, the efficient utilization of which presents a major economic problem, D r . Rals~ton described work t h a t he and his colleagues had done pertinent to the solution of this problem. Their general approach, he said, had been t o synthesize compounds from fatty acids and to a t t e m p t to investigate or predict some of their uses. H e then described work i n which t h e carboxyl group of the fabty acid was treated to effect conversion, to a nitrile
from which amines, q u a t e r n a r y ammonium salts, and a w i d e variety of other compounds can b e produced. Stressing the fact t h a t the conversion of a f a t t y acid to an active p r i m a r y derivative was not merely the synthesizing of one compound, but actually t h e beginning of a new series of derivatives, h e said, "If our present work has merely served to point o u t the great potentialities which exist in this field it will h a v e served well its purpose/ 7 In addition t o those on the program,
Left. A. G. Ring, MalEinckrodt, and Victor Conquest, Armour and Co. Right, Walter J. Murphy, editor. In-
dustrial Burdett,
guests of honor a t the dinner were Carl F . Cori and Gerty T . Cori, E . A. Doisy, St. Louis University, winner of the Nobel P r i z e ; Alden H. E m e r y , secretary of t h e AMERICAN
CHEMICAL
SOCIETY;
Joseph
H . Erlanger, Washington University, winner of the Nobel Prize; Patrick J . Holloran, S.J., president of St. Louis University; L. E . McCauley, vice presid e n t in charge of research of Armour and C o . ; and Walter J . M u r p h y , editor of Industrial and Engineering Chemistry and C H E M I C A L AND E N G I N E E R I N G
NEWS.
and Engineering Chemistry and C&EN; Shell Oil Co., chair man-elect, St. Louis
Robert Section
Chemicals from Fats AINDERSON
No
W.
i OT m a n y years ago the feeling prevailed t h a t fundamental research w a s a prerogative of the universities and the sole function of industrial research! laboratories was to translate these findings into a practical language. I t is a p e r m a n e n t tribute to the greatness of American chemistry t h a t this distinction between university and industrial research h a s disappeared. Industrial leaders have long since learned t h a t the search for fundameotal knowledge is a prerequisite to the continuation of an established enterprise or to "the creation of new fields of endeavor. Tfcie universities, on the other hand, have i&alized that although the acquisition of knowledge m a y be, in itself, a notable contribution, t h e lifeblood of an attainment resides in its adaptation to the many pxoblems which confront mankind. The close cooperation which existed between university and industrial laboratories during the war was certainly a major factor m our victory, and its continuation will "be one of our greatest safeguards for ensuring perman e n t and enduring peace. "Chemicals from Fats'' presents an example of research of a fundamental nat u r e which has been u n d e r t a k e n by an industrial laboratory and -which is being carried to a practical conclusion. Emphasis upon t h e nonedible uses of fats may a p pear to be rather unusual in view of t h e 836
RALSTON,
Armour Research Laboratories, Chicago, III.
dearth of fats a n d oils during the war and in this i m m e d i a t e p o s t w a r period. T h e t r u t h is t h a t in n o r m a l times this country produces an excess of fats and their efficient utilization has long been a major economic p r o b l e m . I t m u s t be admitted, however, t h a t d u r i n g t h e recent m e a t famine I felt t h a t p e r h a p s we have our research p r o b l e m backwards, and t h a t instead of synthesizing "chemicals from cows" we should h a v e been a t t e m p t i n g to synthesize "cows from chemicals". T h e problem of t h e synthesis of chemicals from fats revolves essentially around the fatty acids. T h i s is immediately apparent when o n e considers the chemical structure of a t y p i c a l fat and its component parts as shown below. H 2 COOC(CH 2 ) 1 4 CH 3
3H20
H COOC(CH2)7CH=CH(CH2)7CH3 H2CO0C(CH2)l6CH3 l-Paîmito-2-oleostearin I n the average fat the glycerin constitutes only a p p r o x i m a t e l y 1 0 % of the weight and t h e f a t t y acids account for 9 0 % . T h u s , for every 100 lb. of glycerin obtained by s p l i t t i n g fats 900 lb. of fatty acids are also obtained. Glycerin has CHEMICAL
been an i m p o r t a n t industrial chemical for generations and its uses b o t h in war and in peace are legion. Prior to the reduct i o n of t h e fatty acids to alcohols their only major inedible use was in the production of soaps. A n y research program looking forward to t h e chemical utilization of t h e fats must, therefore, be primarily concerned with these f a t t y acids. Some years ago Armour and Co. realized t h a t t h e relegation of these fatty acids to t h e soap kettles m a y constitute an inefficient use of a valuable product. I t was t h o u g h t t h a t in these acids there m a y reside a material of potential importance for the synthesis of m a n y valuable organic compounds. Our years of work upon these acids have served to justify this b e H2COH CH 3 (CH 2 ) 1 4 COOH Palmitic acid 1 H C OH + CH3(CH2)7CH=CH(CH2)7COOH I Oleic acid HoCOH CHa(CH a )ieCOOH :OH Stearic acid F a t t y Acids Gl> erin lief. Our general approach has been t o synthesize compounds from these acids, t o study t h e physical a n d chemical properties of these compounds, and t o a t t e m p t t o investigate or predict some of their uses. I n the m a t t e r of uses we h a v e been favAND
ENGINEERING
NEWS
ored with t h e cooperation of m a n y u n i versities a n d industrial laboratories. Occurrence and of Fatty slcids
Structures
Before we discuss a n y specific c o m pound, let us consider for a m o m e n t t h e occurrence a n d t h e structures of these fatty acids. F a t t y substances are found universally distributed t h r o u g h o u t t h e animal, vegetable, and marine kingdoms, and t h e y a r e apparently an essential c o m ponent of every living thing. T h e b i o logical synthesis of the fatty acids is a subject w h i c h presents m a n y interesting aspects. T h e ability of plants to s y n t h e size a specific type of acid to t h e a l m o s t complete exclusion of other types is a fact which has never been explained. For ex ample, t h e oil of t h e castor p l a n t is c h a r a c terized b y t h e hydroxy acid ricinoleic acid, whereas t h e oil of the p a l m tree is almost exclusively the s a t u r a t e d acid palmitic a c i d . Although t h e d e p o t fat of animals is somewhat dependent u p o n t h e food consumed, it has been observed t h a t , upon s t a r v a t i o n , all animal fats show a marked resemblance. This indicates t h a t the presence of certain acids is essential to the m a i n t e n a n c e of animal life. There are several generalizations r e garding t h e structures of t h e n a t u r a l l y occurring acids which are w o r t h y of m e n tion. All t h e naturally occurring acids contain a n even number of carbon a t o m s and possess a straight chain of c a r b o n atoms. I t follows, therefore, t h a t t h e derivatives of t h e fatty acids will c o n t a i n this s t r a i g h t chain, the presence of w h i c h is d e t e r m i n a t i v e as regards their chemical and physical properties. Preparation
of
Derivatives
T h e initial step in t h e p r e p a r a t i o n of fatty acid derivatives is t o separate a f a t t y 'd m i x t u r e into its c o m p o n e n t p a r t s , ih separations are generally a c c o m p lished by a continuous v a c u u m distillation and r e s u l t in commercially p u r e acids or in mixtures of closely allied acids. D i s tillation serves t o separate acids of differ ent c h a i n l e n g t h ; it does n o t s e p a r a t e acids of t h e same chain length b u t of dif ferent degrees of saturation. Solvent c r y s tallization is rapidly assuming a role of importance for t h e separation of this l a t t e r t y p e of mixture. Undoubtedly, f u t u r e trends will involve a combination of b o t h fractional distillation and solvent c r y s t a l lization. F a t t y acid derivatives can be r o u g h l y divided i n t o two types. T h e first of t h e s e comprises those compounds which a r e prepared by a modification of t h e h y d r o carbon c h a i n . For example, oleic acid yields dihydroxystearic acid u p o n o x i d a tion, a c o m p o u n d which can be f u r t h e r oxidized to yield a mixture of pelargonic and azelaic acids. T h e latter of these is a nine-carbon-membered dicarboxylic acid and can b e used for t h e synthesis of m a n y V O L U M E
2 5,
NO.
12
*
»
plastics, fibers, and allied materials. T h e second type of fatty acid derivative is t h a t prepared b y a chemical reaction of t h e carboxyl group. This m e t h o d of a t t a c k can yield literally thousands of com pounds, m a n y of which h a v e i m p o r t a n t a n d far-reaching industrial uses. For e x ample, let us follow through one of t h e s e syntheses with t h e p r i m a r y object of pointing o u t its m a n y ramifications. Example
of
Synthesis
When t h e fatty acids are t r e a t e d either in. the liquid or in the v a p o r phase w i t h ammonia a t elevated t e m p e r a t u r e s t h e y are first converted t o amides, which t h e n yield nitriles according to t h e following reaction : Ο
Ο
RC
+ NH3
>- R C
\
•+- H 2 0
X OH
NH2 Amide
^Ο
2RC
RC0ONH4 + RCN N"itrile
NH,
served to convert t h e f a t t y acids into another «pries o f compounds and offers an opening wedge for further synthesis. I t may b e of i n t e r e s t t o mention briefly some of t h e major p r o p e r t i e s of these nitriles. They possess m e l t i n g and boiling p o i n t s appreciably- below those of t h e p a r e n t acids. The presence of t h e triple-bonded nitrogen renders them chemically reactive. They are plasticizers for a v a r i e t y of polymers, t h e nitrile group rendering t h e m compatible w i t h m a n y substances. Cer tain of ttiese compounds, particularly lauronitrile, a r e highly repellent t o in sects. This p r o p e r t y is also possessed b y the higher homologs in spite of t h e fact that they a r e essentially odorless to h u m a n beings. A. distinctive p r o p e r t y of t h e long-chain nitriles is t h a t t h e y c a n be thermally cracked w i t h o u t a loss or modi fication of the polar group b y processes similar to t h o s e employed in t h e petroleum industry for cracking of hydrocarbons. The products consist of b o t h s a t u r a t e d and u n s a t u r a t e d shorter-chain nitriles a n d hydrocarbons from which alcohols, alkyl halides, alkyl thiocyanates, a n d a wide variety of aliphatic compounds can be easily prepared. Hydrogénation of t h e nitriles yields t h e amines o r a l k y l a m m o n i a s , t h e salts of which, are i m p o r t a n t surface-active agents. The high molecular weight amines t h e m selves are insoluble in w a t e r ; however, the appreciable water solubilities of m a n y of their s a l t s make t h e m a n i m p o r t a n t class of organic compounds. S it r/Vx ce -.Λ cti r e A ge η ts U n d o u b t e d l y most of y o u are generally familiar w i t h the properties of surfaceactive agents. Most surface-active agents are chura-cterized b y t h e presence of a long hydrocarbon chain t o which is a t tached art l e a s t one water-solubilizing group. I n dilute aqueous solution t h e y function a s o r d i n a r y electrolytes; how ever, at a, certain critical concentration, which depends u p o n t h e compound in question, a n u m b e r of long-chain ions condense to form an associated particle or micelle. A t t h i s p o i n t >we h a v e an equilibrium b e t w e e n free ions, associated ions, and associated molecules, a n d m a n y of th.e uses of the colloidal electrolytes are dependeirt u p o n t h e presence of those micelles. T h e deterging a n d emulsifying powers of soaps, for example, are depend ent upon t h e presence of soap micelles. The amine s a l t s belong t o t h e class known as cationic colloidal electrolytes. These compounds differ from t h e more common
T h e formation of the nitrile from t h e amide proceeds b y a disproportionation reaction r a t h e r t h a n through a simple d e hydration. This disproportionation is undoubtedly t h e major reaction when amides are decomposed in t h e liquid phase. Our studies of the mechanism of t h e vaporphase formation of nitriles has indicated t h a t the reaction is rather complex. I n t h e vapor phase the reaction rate appar Ο ently depends upon / t h e relative rates of Na CHsCHoCHoCHoCHoCHoCHaCHoCHoCHoCHoC sorption and desorpΌ tion of t h e reactants Sodium l a u r a t e a n d products from a catalytic surface. CHeCHsCHsCHaCHaCHsCHoCHoCHaCHaCHoCI^NHe CI This comparatively simple reaction has Dodecylamirxe h y d r o c h l o r i d e MARCH
2 4,
1947
837
anionic electrolytes, such as soaps, in t h a t t h e long hydrocarbon chain is in t h e positive portion of t h e molecule. T h i s is illustrated by a comparison of t h e s o l u t i o n behaviors of sodium laurate a n d d o decylamine hydrochloride, both of w h i c h contain a straight chain of twelve a t o m s . These two compounds are shown a b o v e . T h e unusual behavior of t h e a m i n e salts is due to t h e fact t h a t t h e long-chain colloidal ions possess a positive c h a r g e . They are strongly adsorbed upon silica and siliceous minerals. Glass t h r e a d s a n d fibers which contain an adsorbed film of amine possess many times t h e t e n s i l e strength of unlubricated fibers. A t r a c e of amine adsorbed upon a siliceous a g g r e gate prevents t h e aggregate from w o r k i n g out of asphalt, so t h a t roads p r e p a r e d with asphalt containing a small a m o u n t of amine or m a d e with a t r e a t e d a g g r e g a t e possess much longer lives t h a n u n t r e a t e d roads. Siliceous types of building m a t e r i als are rendered waterproof by b e i n g soaked in solutions of amine salts. The unusual adsorption characteristics of t h e amine salts h a v e m a d e t h e m i m p o r t a n t flotation agents. I n such processes t h e amine salts generally reverse t h e u s u a l flotation procedure in t h a t it is t h e siliceous mineral or " g a n g u e " which floats. I t is because of this phenomenon t h a t a major proportion of the p h o s p h a t e rock floated in this country is floated b y the amine process. Much of t h e p o t a s h p r o duced in this country is also floated w i t h this reagent. Both potash and p h o s p h a t e s are extremely i m p o r t a n t agricultural chemicals a n d it is of interest t h a t a c h e m ical prepared from fats should b e instrumental in giving back to t h e soil t h e ability to produce more fats. Amines h a v e been found to be very useful c h e m i cals in the beneficiation of iron ores. Potential of Amine
Uses Salts
T h e m a n y uses of t h e a m i n e s a l t s are largely dependent upon their p h y s i c o chemical behavior. Amines c o n t a i n i n g a radioactive carbon would be v e r y useful in a study of this physical b e h a v i o r . T h e synthesis of such amines is n o w u n d e r w a y in our laboratories. An interesting p h e n o m e n o n a s s o c i a t e d with t h e high molecular weight a m i n e s is their ability t o form complexes w i t h t h e salts of heavy metals. I n s u c h c o m p l e x e s t h e high molecular weight amines a r e held b y auxiliary valences, t h e c o m p o u n d s being structurally similar t o t h e m e t a l l i c a m m o n i a complexes originally d e s c r i b e d b y Werner. These complexes c o m b i n e t h e insecticidal a n d fungicidal p r o p e r t i e s of b o t h t h e h e a v y m e t a l s a n d t h e a m i n e s . Recently, t h e y h a v e been shown t o prot e c t cloth a n d fabrics from a t t a c k by molds and rot-producing organisms- Such compounds a r e indicated for use a s seed disinfectants a n d for a v a r i e t y of a g r i c u l t u r a l purposes.
838
When t h e t e r t i a r y amines are treated with alkyl halides, sulfates,, or certain other esters they a r e c o n v e r t e d into q u a ternary a m m o n i u m compounds. The quaternary a m m o n i u m salts c a n be defined as t e t r a - s u b s t i t u t e d a m m o n i u m salts a n d the quaternary a m m o n i u m bases as t e t r a substituted a m m o n i u m hydroxides. Several examples of quaternary ammonium compounds are shown below _ CH;
4N
Basio Ci
C16H33
Trimethylhexadecylammoni"um chloride CH,v
, CI
C12H25' Dimethyldodecylbenzylammonium chloride
%
x ' ^
CI
Hexadecylp3^ridinium chloride CeHi
/NIT-
CÔHIS—Ν ·
CeHia/ 7
T h e q u a t e r n a r y a m m o n i u m compounds are all characterized b y t h e presence of a p e n t a v a l e n t nitrogen a t o m . T h o s e which contain a t least one long-chain alkyl or aikenyl group function as cationic colloidal electrolytes. T h e y all possess extremely high bactericidal p r o p e r t i e s . Fish packed in ice which contains a t r a c e of these com pounds can be s h i p p e d over long distances w i t h o u t deterioration.
CI
T r i h e x y l a z o n i u m chloride
Reaction
All the c o m p o u n d s which I h a v e men tioned result from o n e major reaction of t h e carboxyl g r o u p — n a m e l y , its reaction with a m m o n i a to yield a nitrile. The amines, q u a t e r n a r y ammonium com pounds, a n d a w i d e v a r i e t y of other com pounds a r e the indirect r e s u l t of this one modification. If we realize t h a t when we convert a fatty acid t o a n alcohol, an al dehyde, a n acid chloride, a ketone, or any other p r i m a r y d e r i v a t i v e w e are n o t merely synthesizing one c o m p o u n d b u t , in each case, we a r e a c t u a l l y beginning a n entire series of new d e r i v a t i v e s , we can appre ciate t h e p o t e n t i a l v a l u e of t h e f a t t y acids as a s t a r t i n g p o i n t i n chemical synthesis. If our present w o r k h a s m e r e l y served to p o i n t out the g r e a t potentialities which exist in t h i s field it will» h a v e served well its purpose.
In ml Delivers Howard Lecture at George Washington University E,
iDWix H . L.VXD, presidenx and founder of the Polaroid C o r p . , discTissed " I n d u s t r y as a n O p p o r t u n i t y for -the Combina tion of Physical a n d Social Sciences" during t h e second annual Fzrank A. H o w a r d lecture on i n d u s t r i a l research given by t h e School of Engineering, Oeorge W a s h ington University, in cooperation w i t h the National A c a d e m y of Sciences a n d the National Research Council i n Lisner Audi torium, Washington, D . C, March 3 . The lecture first reviewed briefly the p a r t t h a t Mr. L a n d h a s found basic re search plays in modern s m a l l industry. H e then pointed out that i n spite of the unifying and stimulating effect t h a t a good scientific p r o g r a m has in a company, t h e m a n a g e m e n t still feels that i t s sci entific p r o g r a m is i n a d e q u a t e in making the b e s t use of all t h e personnel i n the corpora tion. He s t a t e d t h a t "it is therefore suggested t h a t j u s t as i n d u s t r y at tb.e turn of the century a d o p t e d the policy of establish ing laboratories for basic research i n the physical sciences, so t h e t i m e has now come for industry t o establish laboratories for basic research in t h e social sciences. I n d u s t r y ' s chief current n e e d is t h e de velopment of i n v e n t i o n s relating people t o machines."
CHEMICAL
E v e n t h o u g h t h e social sciences may seem i m m a t u r e , h e u r g e d t h a t industry will be r e w a r d e d b y t h i s effort, a n d t h a t it seems reasonable t o h o p e t h a t t h e ultimate result of t h i s p r o g r a m will be a new organi zation of i n d u s t r y u n d e r our present eco n o m i c system. I t will b e different in t h a t t h e individual t a l e n t s will be utilized so t h a t each will b e a full p a r t i c i p a n t in s o m e responsible a s p e c t of t h e a c t i v i t y of his i n d u s t r y . T h e r e is no n a t u r a l conspiracy against our finding o u t t h i n g s . " N a t u r e doesn't give a d a m n if we d o or d o n ' t learn; if we d o n ' t solve o u r p r o b l e m s i t is because t h e r e i s n ' t e n o u g h detailed a n d careful scientific research u n d e r w a y . As scien t i s t s we s h o u l d n ' t b e satisfied w i t h any t h i n g b u t the scientific i d e a l . " M r . L a n d w a s i n t r o d u c e d b y F r a n k A. H o w a r d , university a l u m n u s a n d former president of t h e S t a n d a r d Oil Develop m e n t Co., a subsidiary of t h e S t a n d a r d Oil Co. (New J e r s e y ) . M r . H o w a r d is the donor of t h e series of lectures which was launched in 1946. M r . L a n d , a pioneer in industrial ap plication of light polarization, won new prominence last w e e k w i t h t h e announce m e n t of his d e v e l o p m e n t of a camera which produces finished p i c t u r e s .
AND
ENGINEERING
NEWS
