Nonionic esters

This category includes polyoxyethylene glycol esters, sorbitan esters, fatty acid esters of glycols and glycerol, including ethoxylated derivatives, and sugar esters. 

Conversion to fatty acid and alcohol takes place, i.e. polyoxyethylene glycol, sorbitan, glycol or glycerol, sugar. 

Alkali. Conversion to soap and alcohol takes place. Alkaline hydrolysis is of more practical use. 

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Abstract There is a growing demand for hydrolyzable surfactants, i.e., sirnfactants that break down in a controlled way by changing the pH. Environmental concern is the main driving force behind current interest in these sirnfactants, but they are also of interest in applications where sirnfactants are needed in one stage but later undesirable at another stage of a process. This chapter summarizes the field of hydrolyzable sirnfactants with an emphasis on their more recent development. Surfactants that break down either on the acid or on the alkaline side are described. It is shown that the susceptibility to hydrolysis for many surfactants depends on whether or not the surfactant is in the form of micelles or as free unimers in solution. It is shown that whereas nonionic ester sirnfactants are more stable above the CMC (micellar retardation), cationic ester surfactants break down more readily when aggregated than when present as unimers (micellar catalysis). 

Actrol. [Climax Performance] Eth-oxylated nonionic esters emulsifier and lubricity additive for metalworic-ing. 

DepcosoftNP. [Gresco M. ] Nonionic ester napping softener, lubricant for synthetic fiber with scrot y hand. 

Fatty acids or their derivatives are connected to a variety of hydrophilic head groups through esterification of fatty acids or transesterification using fatty acid methyl esters or triglycerides as depicted in Scheme 1.8. Hydrophilic head groups that are used to prepare nonionic ester surfactants fall into several of the following subcategories. 

Nonionic detergents, as the name implies, are not electrolytes, although they do possess the general polar-nonpolar character typical of surfactants. Examples of common types would include polyether esters, for... 

Photoresist appHcations in the microelectronics industry have also been disclosed (340). Thermally stable ben2yl sulfonate esters based on 2-methyl-3-nitroben2otrifluoride [6656-49-1] can serve as nonionic photoacid generators to promote a cascade of reactions during irradiation of the resist. 

Although most greases offer some inherent protection against msting, additives, eg, amine salts, sodium sulfonate, cycloparaffin (naphthenate) salts, esters, and nonionic surfactants (qv), are often used to provide added protection against water and salt-spray corrosion. A dispersion of sodium nitrite has been particularly effective in some multipurpose greases. 

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. 

Inositols, ie, hexaliydrobenzenehexols, are sugars that have received increasing study and are useful in the treatment of a wide variety of human disorders, including vascular disease, cancer, cirrhosis of the Hver, frostbite, and muscular dystrophy (269). Myoinositol esters prepared by reaction with lower fatty acid anhydrides are useful as Hver medicines and nonionic surfactants the aluminum and ammonium salts of inositol hexasulfate are useful anticancer agents (270). Tetraarjloxybenzoquinones are intermediates in the preparation of dioxazine dyes (266,271). The synthesis of hexakis(aryloxy)benzenes has also beenpubUshed (272). 

Lanolin alcohols are obtained by saponification of purified wool grease, a mixture of high molecular esters that is recovered in wool (qv) scouring. Ethoxylation of purified lanolin alcohols yields a full series of lipophilic and hydrophilic nonionic emulsifiers whose largest use is in cosmetic preparations. Manufacturers include Amerchol, Croda, ICI, Henkel Corporation, Westbrook Lanolin, Witco, and Pulcra, SA. 

Cationic, anionic, and amphoteric surfactants derive thek water solubiUty from thek ionic charge, whereas the nonionic hydrophile derives its water solubihty from highly polar terminal hydroxyl groups. Cationic surfactants perform well in polar substrates like styrenics and polyurethane. Examples of cationic surfactants ate quaternary ammonium chlorides, quaternary ammonium methosulfates, and quaternary ammonium nitrates (see QuARTERNARY AMMONIUM compounds). Anionic surfactants work well in PVC and styrenics. Examples of anionic surfactants ate fatty phosphate esters and alkyl sulfonates. 

A series of sorbitol-based nonionic surfactants are used ia foods as water-ia-oil emulsifiers and defoamers. They are produced by reaction of fatty acids with sorbitol. During reaction, cycHc dehydration as well as esterification (primary hydroxyl group) occurs so that the hydrophilic portion is not only sorbitol but also its mono- and dianhydride. The product known as sorbitan monostearate [1338-41 -6] for example, is a mixture of partial stearic and palmitic acid esters (sorbitan monopalmitate [26266-57-9]) of sorbitol, 1,5-anhydro-D-glucitol [154-58-8] 1,4-sorbitan [27299-12-3] and isosorbide [652-67-5]. Sorbitan esters, such as the foregoing and also sorbitan monolaurate [1338-39-2] and sorbitan monooleate [1338-43-8], can be further modified by reaction with ethylene oxide to produce ethoxylated sorbitan esters, also nonionic detergents FDA approved for food use. 

An oral dental riase geaeraHy coasists of water, alcohol, a humectant, an emulsifier, flavor, color, and an active agent. Water is the primary vehicle. The alcohol provides bite and is also a formulation aid. The humectant improves the feel ia the mouth and also prevents locking of the cap to the container between uses glycerin or noncrystaUiziag sorbitol may be satisfactory. The emulsifier is a nonionic type, for example, a polyoxyethylene—polyoxypropylene block copolymer or a polyoxyethylene sorbitan fatty acid ester. Flavors are generally a type of mint or cinnamon. Colors are FD C or D C. 

Surface-Active Agents. Polyol (eg, glycerol, sorbitol, sucrose, and propylene glycol) or poly(ethylene oxide) esters of long-chain fatty acids are nonionic surfactants (qv) used in foods, pharmaceuticals, cosmetics, textiles, cleaning compounds, and many other appHcations (103,104). Those that are most widely used are included in Table 3. 

DBU IS most widely employed as the base m the Barton-Zard reaction Stronger nonionic bases such as PrMeNCH-,CH-j,N and the phosphazene base Csiipplied by Flukai are more effective to induce pyrrole formadon in the reaction of nitroalkenes v/ith isocyano esters than DBU Sterically hindered nitroalkenes are converted into the corresponding pyrroles using these bases, as shovm in Eq 10 35, but DBU is not effective in this transformation... 

Nonionic surfactants like polyethylene glycol esters (PEG) are used as mild cleansers, or to add viscosity to mixtures such as shampoo. 

Higher molecular primary unbranched or low-branched alcohols are used not only for the synthesis of nonionic but also of anionic surfactants, like fatty alcohol sulfates or ether sulfates. These alcohols are produced by catalytic high-pressure hydrogenation of the methyl esters of fatty acids, obtained by a transesterification reaction of fats or fatty oils with methanol or by different procedures, like hydroformylation or the Alfol process, starting from petroleum chemical raw materials. 

Results described in the literature have resulted in several patents, such as one for the improvement of the transport of viscous crude oil by microemulsions based on ether carboxylates [195], or combination with ether sulfate and nonionics [196], or several anionics, amphoterics, and nonionics [197] increased oil recovery with ether carboxylates and ethersulfonates [198] increased inversion temperature of the emulsion above the reservoir temperature by ether carboxylates [199], or systems based on ether carboxylate and sulfonate [200] or polyglucosylsorbitol fatty acid ester [201] and eventually cosolvents which are not susceptible for temperature changes. Ether carboxylates also show an improvement when used in a C02 drive process [202] or at recovery by steam flooding [203]. 

Highly concentrated ether carboxylic acids with a low degree of ethoxylation even at room temperature can give an esterification reaction with the non-converted nonionic, especially with the fatty alcohol, to several percentage points. The result may be that a too low value is found for the ether carboxylate content. This mistake in analysis can be avoided by saponification of the formed ester [238]. Two hundred to 300 mg matter and ca 100 mg NaOH were weighed in a 50-ml Erlenmeyer glass, heated with 20 ml ethanol under reflux, and after cooling supplied with water to 100 ml. Afterward a two-phase titration was carried out. 

LDL compositions containing AOS, a sulfosuccinic acid ester, a zwitterionic and a nonionic surfactant have been described by Noguera et al. [76]. Such compositions have good cleaning and foaming power and are useful too for shampoo and laundry-cleaning purposes. 

This kind of ester acts as a nonionic surfactant if the alkanol groups contain hydrophilic moieties. If only two molecules of alkanoles are added to the phosphoric acid molecule an acid or secondary dialkyl phosphoric acid ester is formed that are an amphiphilic molecule by itself see Eq. (5). 

Phosphoric acid esters of polyoxyalkylenes of a high degree of alkoxylation still show many properties of the base products [37,38], Thus these products derived from nonionics are only mildly anionic. They have a better performance in such applications as institutional and industrial cleansers with a high percentage of alkaline builders. 

Phosphoric acid esters of nonionic surfactants have a greater solubility and compatibility than the nonionics from which they are derived, as shown in Table 3 [37]. 

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