Fatty emulsifier

Detergents may be produced by the chemical reaction of fats and fatty acids with polar materials such as sulfuric or phosphoric acid or ethylene oxide. Detergents emulsify oil and grease because of their abiUty to reduce the surface tension and contact angle of water as well as the interfacial tension between water and oil. Recent trends in detergents have been to lower phosphate content to prevent eutrification of lakes when detergents are disposed of in municipal waste. 

Propylene Glycol Esters. These emulsifiers are formed by an alcoholysis reaction of propylene glycol and fatty acids, and are predominantly used in cakes, prepared mixes, whipped toppings, and breads (36). 

Sucrose Esters. These newer emulsifiers, approved for direct addition in the United States in 1983 (35), ate formed when sucrose is combined with various fatty acids and the resulting emulsion is dehydrated. These additives are odorless and tasteless, and can withstand the retort process. They are used in products when standards of identity do not preclude their use, such as baked goods, baking mixes, dairy product analogues, fto2en dairy desserts and mixes, and whipped milk products (39). High price has limited use in the United States, but these compounds ate used extensively in Japan as emulsifiers in baked goods (40). 

Additives. Because of their versatility, imparted via chemical modification, the appHcations of ethyleneimine encompass the entire additive sector. The addition of PEI to PVC plastisols increases the adhesion of the coatings by selective adsorption at the substrate surface (410). PEI derivatives are also used as adhesion promoters in paper coating (411). The adducts formed from fatty alcohol epoxides and PEI are used as dispersants and emulsifiers (412). They are able to control the viscosity of dispersions, and thus faciHtate transport in pipe systems (413). Eatty acid derivatives of PEI are even able to control the viscosity of pigment dispersions (414). The high nitrogen content of PEIs has a flame-retardant effect. This property is used, in combination with phosphoms compounds, for providing wood panels (415), ceUulose (416), or polymer blends (417,418) with a flame-retardant finish. 

Food. Lecithin is a widely used nutritional supplement rich ia polyunsaturated fatty acids, phosphatidylcholine, phosphatidylethanolamine, phosphatidjhnositol, and organically combiaed phosphoms, with emulsifying and antioxidant properties (38). 

Another microbial polysaccharide-based emulsifier is Hposan, produced by the yeast Candida lipolytica when grown on hydrocarbons (223). Liposan is apparentiy induced by certain water-immiscible hydrocarbons. It is composed of approximately 83% polysaccharide and 17% protein (224). The polysaccharide portion consists of D-glucose, D-galactose, 2-amino-2-deoxy-D-galactose, and D-galacturonic acid. The presence of fatty acyl groups has not been demonstrated the protein portion may confer some hydrophobic properties on the complex. 

Phospholipids. Phospholipids, components of every cell membrane, are active determinants of membrane permeabiUty. They are sources of energy, components of certain enzyme systems, and involved in Hpid transport in plasma. Because of their polar nature, phosphoUpids can act as emulsifying agents (42). The stmcture of most phosphoUpids resembles that of triglycerides except that one fatty acid radical has been replaced by a radical derived from phosphoric acid and a nitrogen base, eg, choline or serine. 

Emulsifiers. Removing the remover is just as important as removing the finish. For water rinse removers, a detergent that is compatible with the remover formula must be selected. Many organic solvents used in removers are not water soluble, so emulsifiers are often added (see Emulsions). Anionic types such as alkyl aryl sulfonates or tolyl fatty acid salts are used. In other appHcations, nonionic surfactants are preferred and hydrophilic—lipophilic balance is an important consideration. 

Defoamers (qv) are available in several forms, composed of many different materials. Historically, paste and soHd defoamers were used extensively. Composed of fatty acids, fatty amides, fatty alcohols, emulsifiers (and mineral oil [8012-95-1] in the high soflds paste emulsions), these defoamers required emulsification (brick) or dilution (paste) before use. Liquid defoamers have become the preferred form, insofar as concern about handling and ovemse have been overcome. 

The second most common alkalinity control agent is lime [1305-78-8] normally in the form of calcium hydroxide [1303-62-0], used in both water and oH muds. In the latter, the lime reacts with added emulsifiers and fatty acids to stabHi2e water-in-oH emulsions. Lime is used in brine systems containing substantial quantities of soluble calcium and in high pH lime muds. Concentrations are ca 6—57 kg/m (2—20 lb /bbl) (see Lime AND LIMESTONE). 

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). 

Emulsifiers are incorporated in oil and synthetic mud formulations to maintain a stable emulsion of the internal brine phase. These materials include calcium and magnesium soaps of fatty acids and polyamines and amides and their mixtures (123,127). The specific chemistry of these additives depends on the nature of the continuous phase of the mud, ie, whether diesel oil, mineral oil, or a synthetic Hquid. Lime is added along with the fatty acid to form the... 

Reaction with Fatty Acids and Esters. Alkanolamines and long-chain fatty acids react at room temperature to give neutral alkanolamine soaps, which are waxy, noncrystaUine materials with widespread commercial appHcations as emulsifiers. At elevated temperatures, 140 —160°C, A/-aIkanolamides are the main products, at a 1 1 reaction ratio (7,8). 

Cosmetics and Personal Care Products. Alkanolamines ate important taw materials in the manufacture of creams (95—97), lotions, shampoos, soaps, and cosmetics. Soaps (98) formed from triethanolamine and fatty acids ate mild, with low alkalinity and excellent detergency. Triethanolamine lauryl sulfate is a common base for shampoos (99—101) and offers significant mildness over sodiumlauryl sulfate. Diethanolamine lauryl sulfate and fatty acid soaps of mono- and trietban olamine can also be used in shampoos and bubble bath formulations. Chemistry similar to that used in soluble oils and other emulsifiers is appUcable to cleansing creams and lotions (102,103). Alkanolamides or salts ate added to the shampoo base to give a smooth, dense foam (104). 

With mineral acids, the alkanolamines form ammonium salts which hydroly2e readily in the presence of water and dissociate on heating. Fatty acids, such as oleic, give soaps which are highly efficient emulsifying agents with important industrial uses, particularly the soaps of AMP (see Emulsions Surfactants). 

These oxazolines have cationic surface-active properties and are emulsifying agents of the water-in-oil type. They ate acid acceptors and, in some cases, corrosion inhibitors (see Corrosion). Reaction to oxazoline also is useful as a tool for determination of double-bond location in fatty acids (2), or for use as a protective group in synthesis (3). The oxazolines from AEPD and TRIS AMINO contain hydroxyl groups that can be esterified easily, giving waxes (qv) with saturated acids and drying oils (qv) with unsaturated acids. 

Fatty amines and derivatives are widely used in the oil field, as corrosion inhibitors, surfactants, emulsifying/deemulsrfying and gelling agents (90). 

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. 

Eatty acid ethoxylates are used extensively in the textile industry as emulsifiers for processing oils, antistatic agents (qv), softeners, and fiber lubricants, and as detergents in scouring operations. They also find appHcation as emulsifiers in cosmetic preparations and pesticide formulations. Eatty acid ethoxylates are manufactured either by alkaH-catalyzed reaction of fatty acids with ethylene oxide or by acid-catalyzed esterification of fatty acids with preformed poly(ethylene glycol). Deodorization steps are commonly incorporated into the manufacturing process. 

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. 

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