Emulsifiers stearic acid

Is a strongly hydrophilic emulsifier and antistat used as an emulsifier in metal buffing compounds. In latex rubber compounding it is used to emulsify stearic acid and to prevent premature coagulation in mild acid or salt baths. 

Sorhita.n nd Sorbitol Esters. This group of emulsifiers is formed from the reaction of sorbitan and stearic acid. Sorbitan monostearate is often used in combination with polysorbate in ice cream, imitation dairy products, and baking appHcations (36). 

The most commonly used emulsifiers are sodium, potassium, or ammonium salts of oleic acid, stearic acid, or rosin acids, or disproportionate rosin acids, either singly or in mixture. An aLkylsulfate or aLkylarenesulfonate can also be used or be present as a stabilizer. A useful stabilizer of this class is the condensation product of formaldehyde with the sodium salt of P-naphthalenesulfonic acid. AH these primary emulsifiers and stabilizers are anionic and on adsorption they confer a negative charge to the polymer particles. Latices stabilized with cationic or nonionic surfactants have been developed for special apphcations. Despite the high concentration of emulsifiers in most synthetic latices, only a small proportion is present in the aqueous phase nearly all of it is adsorbed on the polymer particles. 

Other additives that may be incorporated include sodium hydrogen phosphates as buffering agents to stabilise that pH of the reaction medium, lauryl mercaptan or trichlorethylene as chain transfer agents to control molecular weight, a lubricant such as stearic acid and small amounts of an emulsifier such as sodium lauryl sulphate. 

Heat the oil phase and water phase to about 65° C. Add the oil phase slowly to the aqueous phase with stirring to form a crude emulsion. Cool to about 50°C and homogenize. Cool with agitation until congealed. Note In this classic preparation, the stearic acid reacts with the alkaline borate to form the emulsifying stearate soap. VIII. Paste (zinc oxide paste, USP) Zinc oxide 25%... 

Pentaerythritol Ester As with glycerol esters, the esters are produced by esterification of pentaerythritol with the desired fatty acids. For example, under defined reaction conditions and use of stearic acid in defined concentration, pentaerythritol distearate has been recently developed as an off-white wax with very weak odor (Cutina PES). This type of product is offered as co-emulsifier and consistency factor for cosmetic products with high sensorial elegance and can be applied in various formulations (Fig. 4.17). 

At a pharmaceutical manufacturing facility in New York, an organoclay-carbon filtration system was installed to treat wastewater contaminated with emulsified white petroleum, stearic acid, fatty acid stearates, fatty alcohols, mineral oils, and oxyethylene ethers and stearates. The system consisted of 159 kg of organoclay and 86 kg of activated carbon. The entire system cost 8000 (D17267S, p. 29). 

Structure Forming Excipient An excipient which participates in the formation of the structural matrix which gives an ointment, cream or gel etc., its semisolid character. Examples are gel fonning polymers, petrolatum, certain colloidal inorganic solids (e.g., bentonite), waxy solids (e.g., cetyl alcohol, stearic acid), and emulsifiers used in creams. 

Palmitic add finds use in the production of cosmetics, food emulsifiers, pharmaceuticals, plastics, and soaps. One commercial formulation contains 95% palmitic add, 4% stearic acid, and 1% myristic acid another preparation contains 50% palmitic acid and 50% stearic acid. 

Moisturizers and other similar stay-on products have often pH between 4 and 6. That pH-range is similar to skin surface pH and is often suitable for good physical stability of the cosmetic product. However, there are several moisturizing creams with world-wide acceptance, which have pH of about 7 or even 8, for example, those with stearic acid as the main emulsifier. Also skin protectants based upon zinc oxide often have an alkaline pH. 

The emulsifying agent was prepared from stearic acid and triethanolamine. Give the name of this salt. Write its formula. 

Solid lipids, emulsifiers, and water are generally the ingredients involved for manufacturing SLNs. The term lipids is used in a broader sense and includes triglycerides (e.g., stearin), partial glycerides (e.g., Imwitor), fatty acids (e.g., stearic acid), steroids (e.g., cholesterol), and waxes (e.g., cetyl palmitate). All categories of emulsifiers may be used to stabilize the lipid dispersion, and the combination of emulsifiers prevents particle agglomeration more efficiently. The choice of the emulsifier depends on the administration route and is more limited for parenteral administration. 

Polystyrene beads (PS) are employed as physical templates for macropore. The emulsifier-tee emulsion polymerization method used here allows for the synthesise of nearly monodisperse latex beads of PS in the size of ca. 100 nm [10]. PS beads were prepared using 700 ml degassed water, 54 ml styrene monomer, 0.65 g potassium persulhite as initiator, and 20 ml divinylbenzene as cross-linkmg agent. PS beads were obtained at 70°C and 350 rpm, and dried under ambient condition. Aluminum fec-butoxide and stearic acid were separately dissolved in parent alcohol,. rec-butyl alcohol, at room tempature, and then the two solutions were mixed. Appropriate amount of HNO solution was dropped into the mixture at a rate of I ml/min to acidify and hydrolyze the aluminum precursor. PS beads were added into aluminum hydroxide solution after stirring for 10 h. The final pH of the reactant was approximately 7. Organic templates, both stearic acid and PS bead, were easily removed tern dried aluminum hydroxide by calcination. The overall synthetic procedure is as shown in Fig. 1. 

The active portion of this class of emulsifiers is the anion. In general, these emulsifiers are more acid-stable and permit adjustment of the emulsion pH level to the desirable range of 4.5 and 6.5. Common examples include sodium lauryl sulfate and soaps such as triethanolamine stearate. Triethanolamine stearate is one of the most popular emulsifiers for creams and lotions in use today. It is usually prepared in situ during manufacture from stearic acid in the hot oil phase and from triethanolamine in the hot aqueous phase. The amount of triethanolamine controls the pH level of the resulting product. 

Diethyl sebacate is an emulsifier used in cosmetics and topical medicaments. In contrast to the emulsifying agents stearyl alcohol, stearic acid, and glyceryl stearate, diethyl sebacate is considered to be a rare sensitizer. 

Fitzhugh OG, Bourke AR, Nelson AA, Frawley JP. Chronic oral toxicities of four stearic acid emulsifiers. Toxicol Appl Pharmacol 1959 1 315-331. 

In topical formulations, stearic acid is used as an emulsifying and solubilizing agent. When partially neutralized with alkalis or triethanolamine, stearic acid is used in the preparation of creams. The partially neutralized stearic acid forms a creamy base when mixed with 5-15 times its own weight of aqueous liquid the appearance and plasticity of the cream being determined by the proportion of alkali used. 

When mixed in equimolar proportions with a fatty acid, such as stearic acid or oleic acid, triethanolamine forms an anionic soap with a pH of about 8, which may be used as an emulsifying agent to produce fine-grained, stable oil-in-water emulsions. Concentrations that are typically used for emulsification are 2-4% v/v of triethanolamine and 2-5 times that of fatty acids. In the case of mineral oils, 5% v/v of triethanolamine will be needed, with an appropriate increase in the amount of fatty acid used. Preparations that contain triethanolamine soaps tend to darken on storage. However, discoloration may be reduced by avoiding exposure to light and contact with metals and metal ions. 

Use Intermediate for stearic acid detergents, emulsifiers, wetting agents, stabilizers, resins, lubricants, plasticizers. 

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