Showing papers by "Daniel Swern published in 1952"

Application of urea complexes in the purification of fatty acids, esters, and alcohols. II. Oleic acid and methyl oleate from olive oil

Abstract: Oleic acid and methyl oleate of high purity (97–99%) and substantially free (0.2% or less) of polyunsaturated contaminants have been isolated in 60–70% yield from the fatty acids or methyl esters of olive oil by procedures which require only one precipitation of urea complexes (single dose of urea technique) one low-temperature crystallization, and one fractional distillation. The best yields of the highest purity acids are obtained when saturates are removed by fractional crystallization prior to a final distillation. The urea complex separation technique can be applied directly to olive oil methanolysis reaction mixtures without prior isolation of the mixed methyl esters.

Application of urea complexes in the purification of fatty acids, esters, and alcohols. I. Oleic acid from inedible animal fats

Abstract: Urea complex formation has been employed in the preparation of purified oleic acid (oleic acid content, 80–95%) from various grades of inedible animal fats and red oils. Since the urea complex of oleic acid forms in good yield at room temperature, low temperatures are not required in the isolation procedure. Yields of oleic acid are equal to or lower than those obtained by conventional low-temperature crystallization procedures, but the preparation of a polyunsaturate-free oleic acid is apparently not possible by urea complex formation alone. The separation of polyunsaturated acids from oleic acid by urea complex formation is more convenient than but not as efficient as by solvent crystallization, but separation of saturated acids from unsaturated acids is less convenient. Advantages and disadvantages in using urea in the preparation of purified oleic acid are briefly discussed.

Trans-octadecenoic acid content of beef fat. Isolation of elaidic acid from oleo oil.

Abstract: Infrared spectrophotometric examination of three samples of freshly-rendered edible beef fat, and of edible oleo oil and oleo stearine obtained from one of them, has revealed the presence of substantial quantities (5 to 10%) of trans materials believed to the mainly, if not exclusively, monounsaturated. It has been concluded that the trans components are neither minor nor adventitious constituents but important naturally-occurring components which may contribute to any unique properties which beef fat may have.

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

Abstract: Conditions 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.

Polymerizable derivatives of long‐chain fatty acids. VII. Copolymerization of vinyl acetate with some long‐chain vinyl esters

Abstract: A study was made of the copolymerization of vinyl acetate with vinyl palmitate, vinyl stearate, and vinyl oleate, respectively, True copolymerization was shown to have occurred on the basis of the solubility characteristics of the crude copolymers over a wide range of compositions. The monomer reactivity ratios for the comonomers vinyl palmitate (r1) and vinyl acetate (r2) were determined by two methods. One, based on an analysis of the copolymer, gave r1 = 0.78 ± 0.10 and r2 = 1.15 ± 0.13; the other, based on an analysis for each monomer in the mixture remaining after polymerization, gave r1 = 0.66 ± 0.07 and r2 = 0.84 ± 0.10. When the vinyl palmitate or vinyl stearate content of the copolymer exceeded about 20–25 mole per cent, the copolymers exhibited first-order transition points which were determined using a refractive index technique as well as a polarizing microscope method. Where no transition point could be observed, brittle point measurements were made.