John T. Scanlan

Mechanism of the reactions of oxygen with fatty materials. Advances from 1941 through 1946

SummaryA review of advances from 1941 through 1946 in the mechanism of the oxygen oxidation of fatty materials is given. Subjects discussed are the oxidation of monounsaturated compounds, nonconjugated and conjugated polyunsaturated compounds, and saturated compounds.The hydroperoxide theory of oxidation at active methylene groups is discussed in detail. There is good justification for postulating that autoxidative attack in olefins isinitiated universally by addition of oxygen at the double bonds in only afew of the molecules, and not by the formation of hydroperoxides. Subsequently, in the case of monoolefins and nonconjugated polyolefins, the attack by oxygen is continued bysubstitution on the α-methylene group to form hydroperoxides by means ofchain reactions. Mechanisms for such an oxidative scheme, involving the formation of intermediate free radicals, are given. In the case of conjugated compounds, peroxides are formed by addition of oxygen at the double bonds, and α-methylene group peroxidation does not occur. Although saturated compounds are relatively inert, they also form hydroperoxides, which are converted mainly to ketones and alcohols with the ketones predominating.The formation of polymers, which often account for the major proportion of the oxidation products of unsaturated compounds, also is discussed. The possibility of formation of carbon-to-carbon-linked as well as oxygen-linked polymers in the various classes of olefins is considered.

Fatty acid amides. IV. Reaction of fats with ammonia and amines

SummaryConditions have been worked out for the quantitative conversion of oleo oil, olive oil, castor oil, and tobacco seed oil to amides and glycerol by reaction with liquid ammonia under pressure. Similarly methyl oleate has been converted to oleamide in excellent yield. The reaction of aqueous ammonia with methyl oleate, however, gives a maximum yield of isolated oleamide of only 50%, apparently because of competition between hydrolytic and ammonolytic reactions.N-(2-hydroxyethyl)- and N-(n-dodecyl) amides have also been prepared by the reaction of oleo oil with monoethanolamine andn-dodecylamine, respectively, at atmospheric pressure. Particularly significant is the quantitative conversion of oleo oil to N-(2-hydroxyethyl) amides by refluxing with monoethanolamine for only 15 minutes. The conversion to N-(n-dodecyl) amides however required three hours heating at 230° C. withn-dodecylamine, and conversion to unsubstituted amides required six hours heating at 170°C. under pressure with liquid ammonia.Crystallization of the amides obtained from the various fats yielded oleamide (purity, 92%) from olive oil, ricinoleamide (purity, >95%) from castor oil, and N-(2-hydroxyethyl) oleamide (purity, 90%) from oleo oil. Little fractionation was accomplished with the amides of tobacco seed oil however. In the fractionation of the unsubstituted and N-(n-dodecyl) amides from oleo oil, fractions which were predominantly saturated and monounsaturated were obtained readily, but no greater purification could be effected by recrystallization.Unsubstituted and N-(2-hydroxyethyl) amides were readily converted to the corresponding free acids by refluxing for two hours with constant boiling (approximately 20%) aqueous hydrochloric acid.

Selective hydrogenation in the preparation of purified oleic acid from animal fats. Elimination of extremely low crystallization temperatures

SummaryA procedure is described by which a product containing at least 95% oleic acid can be prepared from animal fats. In this process crystallization of the oleic acid itself is not required, and therefore temperatures below−20°C. are not necessary. This constitutes a decided improvement over previously described processes, which require much lower temperatures.In this procedure the fatty acids, obtained by hydrolysis of inedible tallow or grease which has been selectively hydrogenated until its content of polyunsaturates is less than 1%, are crystallized from acetone at temperatures from 0° to −20°C. to precipitate the solid acids. These acids, which amount to about 50% of the starting material, are equivalent to “double- or triple-pressed stearic acid.”The liquid acids obtained from the filtrate usually contain 90% oleic acid and when fractionally distilled yield a product containing at least 95% oleic acid. Evidence is presented to show that this purified product contains isomeric oleic acids, although cis-9,10-octadecenoic acid undoubtedly predominates.The purified oleic acid is odorless and ranges from colorless to pale yellow, depending upon the quality of the starting material. In addition, it has remarkable color and odor stability. This suggests its use where these quelities are especially desirable, such as in many applications in the textile industry, in cosmetics and in pharmaceuticals. Also, these purified products would be more suited for use as chemical intermediates than the oleic acid (red oil) commercially available at present.

Fractionation of tallow fatty acids. Preparation of purified oleic acid and an inedible olive oil substitute

SummaryTallow fatty acids have been fractionally crystallized from acetone at temperatures ranging from 0° to −60° C.By crystallizing at 0° to −20° C., a saturated acid fraction which amounts to 40 to 50% by weight of the starting material has been obtained. This fraction corresponds to “double- or triple-pressed stearic acid.”The filtrate acids from the crystallization at −20° C. contain over 90% of the oleic acid present in the starting material, and in fatty acid composition this mixture is similar to olive oil. From this fraction. which amounts to about 50% by weight of the starting material, a synthetic triglyceride with, properties approximating those of olive oil has been prepared.By low-temperature crystallization of this oleic-acid-rich fraction at −50° to −60° C., followed by fractional distillation, a good yield of purified oleic acid (oleic acid content, over 95%) has been obtained.

Isolation of an hydroxy acid concentrate from wool wax acids

SummaryThe fractionation of the methyl esters of wool wax acids by partitioning between two immiscible solvent layers has been described. Three fractions were obtained: a fraction rich in hydroxyl content, a fraction low in hydroxyl content, and a small amount of hard, transparent, highly colored material. The same procedure when applied to the free wool wax acids did not yield a satisfactory hydroxy acid concentrate.The preparation of wool wax acids with an essentially zero ester number, that is, in a form free of estolides, lactides, and lactones has also been described.

Preparation and solubility of metal soaps of wool wax acids

The preparation and solubility determination of the cupric, magnesium, nickel, cobalt, cadmium, lead, barium, manganous, ferric, and chromic soaps of the wool wax acid fraction are described. Solubilities, at 25°, were determined in: ethanol, methanol, isopropyl alcohol, acetone, ethyl acetate, carbon tetrachloride, and petroleum ether. Barium and cadmium soaps of hydroxy and nonhydroxy acid fractions, obtained by partitioning the whole wool wax acid fraction, were also prepared and subjected to the same study.

The fractionation of lanolin with urea

SummaryA fractionation of lanolin was effected by contacting lanolin with urea in the presence of methyl alcohol. About 6–8% of the lanolin formed a urea adduct which, upon decomposition, yielded a hard, nontacky wax fraction. In addition to the wax fraction, a fluid fraction and a sticky semi-solid were also obtained. The latter two fractions were obtained by the solvent extraction of the nonadduct-forming material from the urea adducts.The fluid fraction, obtained in 71% yield, is a viscous liquid at room temperature. The fluid properties of the fraction can be improved by acetylation.

Metal soaps of wool wax acids as stabilizers for plasticized polyvinyl chloride

Copper, magnesium, lead, nickel, cobalt, manganese, iron, chromium, cadmium, and barium soaps of the wool wax acid fraction have been tested as stabilizers for plasticized polyvinyl chloride polymers. Barium, cadmium, and lead soaps performed well in the light stability evaluations. In the heat aging tests barium, magnesium, lead, and nickel soaps were superior while cadmium, and manganese soaps performed poorly. The copper, cobalt, iron, and chromium soaps were ineffective.Two tests for stability were employed: an accelerated light aging test and an accelerated heat aging test. Combinations of barium and cadmium soaps were tested for synergistic effects and found to be more effective as stabilizers than the individual soaps. Soaps made from fractions of acids by partitioning the whole wool wax acid fraction were also tested. Neither the hydroxy nor the non-hydroxy acid fraction soaps had as goad stabilizing properties for PVC as those of the whole acid fraction.

The sodium reduction of wool wax

SummaryThe sodium reduction technique has been modified for application to various grades of lanolin and wool grease. The improved process gives good yields of alcohols with low ester and acid numbers. The sterols present in the grease are not affected by the reduction. A recovery procedure is described which avoids the difficulties with extremely stable emulsions. The essential features of this procedure are the elimination of emulsion-stabilizing sodium soaps by precipitation with barium chloride prior to the washing of the reduction mixture and acetone extraction of the alcohols from the insoluble barium soaps.