Esters fatty acid

Lecithins are fatty acid esters of glycero-phosphoric acid derivatives. Commercially glycerophosphoric acid is used to prepare the medicinal glycerophosphate salts, c.g. the calcium salt. 

Reformatski reaction Aldehydes and ketones react with a-bromo- fatty acid esters in the presence of zinc powder to give -hydroxy-esters which may be dehydrated to give a-, 0-unsaturated esters. a-Chloroesters will react if copper powder is used in conjunction with the zinc. 

The intermediate m hydrogenation formed by reaction of the unsaturated ester with the hydrogenated surface of the metal catalyst not only can proceed to the saturated fatty acid ester but also can dissociate to the original ester having a cis double bond or to its trans stereoisomer Unlike polyunsaturated vegetable oils which tend to reduce serum cholesterol levels the trans fats produced by partial hydrogenation have cholesterol raising effects similar to those of saturated fats... 

Fatty acids normally occur naturally as esters fats oils phospholipids and waxes all are unique types of fatty acid esters There is however an important class of fatty acid derivatives that exists and carries out its biological role m the form of the free acid This class of fatty acid derivatives is described m the following section... 

In certain brilliantine compositions, vegetable and animal oils are used as substitutes for mineral oil. In these systems, because of their potential for rancidity, antioxidants must be included. Other alternatives to mineral oils that have found utiHty in brilliantines are the polyethylene glycols which come in a variety of solubiHties and spreading properties. Use of these materials offers the advantage of chemical stabiHty to rancidity. Other additives found in brilliantines to improve their aesthetics include colorants, fragrance, medicated additives, lanolin, and fatty acid esters. 

Many PVC stabilizer formulations also contain one or more organic costabilizers that can also absorb hydrogen chloride. Typical of these additives are epoxidized fatty acid esters and organophosphites ... 

Lignites and lignosulfonates can act as o/w emulsifiers, but generally are added for other purposes. Various anionic surfactants, including alkylarylsulfonates and alkylaryl sulfates and poly(ethylene oxide) derivatives of fatty acids, esters, and others, are used. Very Httle oil is added to water-base muds in use offshore for environmental reasons. A nonionic poly(ethylene oxide) derivative of nonylphenol [9016-45-9] is used in calcium-treated muds (126). 

To overcome these difficulties, drilling fluids are treated with a variety of mud lubricants available from various suppHers. They are mostly general-purpose, low toxicity, nonfluorescent types that are blends of several anionic or nonionic surfactants and products such as glycols and glycerols, fatty acid esters, synthetic hydrocarbons, and vegetable oil derivatives. Extreme pressure lubricants containing sulfurized or sulfonated derivatives of natural fatty acid products or petroleum-base hydrocarbons can be quite toxic to marine life and are rarely used for environmental reasons. Diesel and mineral oils were once used as lubricants at levels of 3 to 10 vol % but this practice has been curtailed significantly for environmental reasons. 

Bisamides. Methylenebisamides are prepared by the reaction of the primary fatty amide and formaldehyde in the presence of an acid catalyst. AijAT-Methylenebisoleamide has been made via this route without the use of refluxing solvent (55). Polymethylenebisamides can be made from fatty acid, esters, or acid haUdes with diamines while producing water, alcohol, or mineral acid by-products. Eatty acids and diamines, typically ethylenediamine, have been condensed in the presence of NaBH and NaH2P02 to yield bisamides (56). When stearic acid, ethylenediamine, and methyl acetate react for 6 h at... 

Other processing aids utilized in tires are vegetable oils (fatty acids, fatty acid esters/alcohols, and metal salts of these oils), naturally occurring resins such as pine tar, hydrocarbon resins from petroleum stUlbottoms, and vulcanized vegetable oils (WOs). WOs were utilized heavily in the early 1900s, but are no longer used extensively in tires. 

Olestra is prepared by a solvenfless transesterification process in which sucrose is treated with methyl ester of fatty acids in the presence of sodium methoxide between 100—180°C for 14 hours (68). The manufacturing process involves removal of the unreacted fatty acid esters by enzymic hydrolysis... 

Enzymatic acylation reactions offer considerable promise in the synthesis of specific ester derivatives of sucrose. For example, reaction of sucrose with an activated alkyl ester in /V, /V- dim ethyl form am i de in the presence of subtilisin gave 1 -0-butyrylsucrose, which on further treatment with an activated fatty acid ester in acetone in the presence of Hpase C. viscosum produced the 1, 6-diester derivative (71,72). 

A major pharmaceutical use of poly(oxyethylene) sorbitan fatty acid esters is in the solubilization of the oil-soluble vitamins A and D. In this way, multivitamin preparations can be made which combine both water- and oil-soluble vitamins in a palatable form. 

Emulsions of fatty- and petroleum-based substances, both oils and waxes, of the o/w type are made by using blends of sorbitan fatty esters and their poly(oxyethylene) derivatives. Mixtures of poly(oxyethylene(20)) sorbitan monostearate (Polysorbate 60) and sorbitan monostearate are typical examples of blends used for lotions and creams. Both sorbitan fatty acid esters and their poly(oxyethylene) derivatives are particularly advantageous in cosmetic uses because of their very low skin irritant properties. Sorbitan fatty ester emulsifiers for w/o emulsions of mineral oil are used in hair preparations of both the lotion and cream type. Poly(oxyethylene(20)) sorbitan monolaurate is useflil in shampoo formulations (see Hairpreparations). Poly(oxyethylene) sorbitan surfactants are also used for solubilization of essential oils in the preparation of colognes and after-shave lotions. 

Vatty Acids andFattyAcidLsters. Sulfolane exhibits selective solvency for fatty acids and fatty acid esters which depends on the molecular weight and degree of fatty acid unsaturation (40—42). AppHcations for this process are enriching the unsaturation level in animal and vegetable fatty oHs to provide products with better properties for use in paint, synthetic resins, food products, plastics, and soaps. 

Sodium fatty acid ester sulfonates are known to be highly attractive as surfactants. These have good wetting abiHty and exceUent calcium ion stabiHty as weU as high detergency without phosphates, and are used in powders or Hquids. They can also be used in the textile industry, emulsion polymerization, cosmetics, and metal surface fields. Moreover, they are attractive because they are produced from renewable natural resources and their biodegradabiHty is almost as good as alkyl sulfates (134—137). 

Fatty JicidFster Sulfonates. Fatty acid ester sulfonates (FAES) are generally produced from methyl esters, ie, methyl ester sulfonate (MES) and prepared via sulfonation, followed by bleaching and neutralization, in a relatively difficult and complex process ... 

Commercial polyoxyethylene fatty acid esters contain varying proportions of monoesters,... 

Ethoxylated Anhydrosorbitol Esters. Ethoxylation of sorbitan fatty acid esters leads to a series of more hydrophilic surfactants (Table 19). All hydroxyl groups of sorbitan can react with ethylene oxide. The stmcture of the principal component of a nominal polyoxyethylene (20) sorbitan monostearate illustrates the composition of these products, where w x y z = 20. 

Typical commercial ethoxylated sorbitan fatty acid esters are yellow Hquids, except tristearates and the 4- and 5-mol ethylene oxide adducts which are light tan soHds. These adducts, as well as the 20-mol adducts of the triesters, are insoluble but dispersible in water. The monoester 20-mol adducts are water soluble. Ethoxylated sorbitan esters are widely used as emulsifiers, antistatic agents, softeners, fiber lubricants, and solubilizers. In combination with the unethoxylated sorbitan esters or with mono- or diglycetides, these are often used as co-emulsrfiers. The ethoxylated sorbitan esters are produced by beating sorbitan esters with ethylene oxide at 130—170°C in the presence of alkaline catalysts. 

Provitamin D. Provitamin is made from cholesterol, and its commercial production begias with the isolation of cholesterol from one of its natural sources. Cholesterol occurs ia many animals, and is generally extracted from wool grease obtained by washing wool after it is sheared from sheep. This grease is a mixture of fatty-acid esters, which contain ca 15 wt % cholesterol. The alcohol fraction is obtained after saponification, and the cholesterol is separated, usually by complexation with 2iac chloride, followed by decomplexation and crystallisation. Cholesterol can also be extracted from the spiaal cords and brains of animals, especially catde, and from fish oils. 

Sorbitol is the most important higher polyol used in direct esterification of fatty acids. Esters of sorbitans and sorbitans modified with ethylene oxide are extensively used as surface-active agents. Interesteritication of fatty acid methyl esters with sucrose yields biodegradable detergents, and with starch yields thermoplastic polymers (36). 

Jojoba is a desert crop that gives a small bean containing about 50% of a wax, a fatty acid ester with a fatty alcohol. The only other large source of such a wax is sperm whale oil, traditionally used in fine lubricants (see Lubrication and lubricants). Because the sperm whale is an endangered species, relatively Httle sperm whale oil is available and there is a large market for a substitute. Jojoba oil has been found to be usable for most of these appHcations. The jojoba oil is obtained by simply pressing the nut followed by conventional refining. Some jojoba oil is used in cosmetics (qv). 

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