Temperature ethoxylation

These proprietary catalysts are more expensive because they must be manufactured rather than simply purchased. Certain catalysts must also be removed from the finished ethoxylate via filtration in order to obtain a clear, transparent ethoxylate. On the other hand, complex catalysts can be significantly more reactive than hydroxide catalysts so that the ethoxylation reaction proceeds in less time, with less catalyst, and at lower temperatures. Ethoxylation with complex catalysts is accomplished via conventional ethoxylation equipment and procedures. 

The stmctural architecture of siUcone polymers, such as the number of D, T, and Q sites and the number and type of cross-link sites, can be deterrnined by a degradative analysis technique in which the polymer is allowed to react with a large excess of a capping agent, such as hexamethyidisiloxane, in the presence of a suitable equiUbration catalyst (eq. 38). Triflic acid is often used as a catalyst because it promotes the depolymerization process at ambient temperature (444). A related process employs the KOH- or KOC2H -catalyzed reaction of siUcones with excess Si(OC2H )4 (eq. 39) to produce ethoxylated methylsiUcon species, which are quantitatively deterrnined by gc (445). 

Fig. 1. Sulfonated and sulfated acid products viscosities after 98% conversions at varying temperatures where the vertical line indicates the maximum temperature for batch sulfonation using SO to minimi2e color deterioration lines A—C represent branched C 2 alkyl ben2ene (BAB) sulfonic acid from SO, oleum (settied), and oleum (whole mixture), respectively lines D and E, lauryl alcohol 3-ethoxylate sulfuric ester (SO ) and lauryl alcohol sulfuric ester...

At room temperature, ca 60 wt % ethylene oxide is needed to solubilize the fatty acids. Surface activity of the ethoxylates is moderate and less than that of alcohol or alkylphenol ethoxylates (84). The ethoxylates are low foamers, a useful property in certain appHcations. Emulsification is the most important function. Its importance is reflected in the wide range of lipophilic solubiHties available in the commercial products. Like all organic esters, fatty acid ethoxylates are susceptible to acid and alkaline hydrolysis. 

Natural Ethoxylated Fats, Oils, and Waxes. Castor oil (qv) is a triglyceride high in ticinoleic esters. Ethoxylation in the presence of an alkaline catalyst to a polyoxyethylene content of 60—70 wt % yields water-soluble surfactants (Table 20). Because alkaline catalysts also effect transestenfication, ethoxylated castor oil surfactants are complex mixtures with components resulting from transesterrfication and subsequent ethoxylation at the available hydroxyl groups. The ethoxylates are pale amber Hquids of specific gravity just above 1.0 at room temperature. They are hydrophilic emulsifiers, dispersants, lubricants, and solubilizers used as textile additives and finishing agents, as well as in paper (qv) and leather (qv) manufacture. 

Ethoxylation of alkyl amine ethoxylates is an economical route to obtain the variety of properties required by numerous and sometimes smaH-volume industrial uses of cationic surfactants. Commercial amine ethoxylates shown in Tables 27 and 28 are derived from linear alkyl amines, ahphatic /-alkyl amines, and rosin (dehydroabietyl) amines. Despite the variety of chemical stmctures, the amine ethoxylates tend to have similar properties. In general, they are yellow or amber Hquids or yellowish low melting soHds. Specific gravity at room temperature ranges from 0.9 to 1.15, and they are soluble in acidic media. Higher ethoxylation promotes solubiUty in neutral and alkaline media. The lower ethoxylates form insoluble salts with fatty acids and other anionic surfactants. Salts of higher ethoxylates are soluble, however. Oil solubiUty decreases with increasing ethylene oxide content but many ethoxylates with a fairly even hydrophilic—hydrophobic balance show appreciable oil solubiUty and are used as solutes in the oil phase. 

The ethoxyl content is controlled by the ratio of reactants and to a lesser degree by the reaction temperature. 

As already mentioned, there is a striking difference in the reactivity of 1- and 3-chloroisoquinoline the former reacts about 10 times faster than the latter with both piperidine and ethoxide ion at room temperature. The lower rate of ethoxy-dechlorination of the 3-isomer is due to an E which is 10 kcal higher. It is not justified to conclude that this isomer is virtually unactivated when its rate of ethoxylation is 100,000 times that of 2-chloronaphthalene and the E for this reaction is markedly decreased (by 7 kcal) relative to that of 2-chloronaphthalene. A direct comparison of reactivity with piperidine has not been made, but a rate ratio of 500 1 can be estimated by using a factor of one-fortieth (Table X, lines 1 and 4) to make the... 

The rate of amination and of alkoxylation increases 1.5-3-fold for a 10° rise in the temperature of reaction for naphthalenes (Table X, lines 1, 2, 7 and 8), quinolines, isoquinolines, l-halo-2-nitro-naphthalenes, and diazanaphthalenes. The relation of reactivity can vary or be reversed, depending on the temperature at which rates are mathematically or experimentally compared (cf. naphthalene discussion above and Section III,A, 1). For example, the rate ratio of piperidination of 4-chloroquinazoline to that of 1-chloroisoquino-line varies 100-fold over a relatively small temperature range 10 at 20°, and 10 at 100°. The ratio of rates of ethoxylation of 2-chloro-pyridine and 3-chloroisoquinoline is 9 at 140° and 180 at 20°. Comparison of 2-chloro-with 4-chloro-quinoline gives a ratio of 2.1 at 90° and 0.97 at 20° the ratio for 4-chloro-quinoline and -cinnoline is 3200 at 60° and 7300 at 20° and piperidination of 2-chloroquinoline vs. 1-chloroisoquinoline has a rate ratio of 1.0 at 110° and 1.7 at 20°. The change in the rate ratio with temperature will depend on the difference in the heats of activation of the two reactions (Section III,A,1). 

Krafft temperatures depend not only on chain length but on the cation. Eth-oxylation of the base alcohol reduces the Krafft temperature due to the higher solubility of the sulfate. Calcium and other earth alkaline metals produce an increase of the Krafft temperature that is significantly reduced by ethoxylation of the alcohol. The decrease is more significant for alkaline earth metals than for alkaline cations as shown in Table 6 [81,82], although it should be noted that, according to other workers, sodium dodecyl sulfate has a Krafft temperature of 16°C. 

For cosmetic compositions an ether carboxylate is used, derived from a fatty acid monoethanolamide [35]. It is known that the ethoxylation takes place on the OH and not on the NH of the ethanolamide group. Due to the acid H atom a narrow range distribution is obtained. The carboxymethylation is carried out with NaOH and SMCA, followed by a washing step with an aqueous solution of a strong acid at high temperatures. The ether carboxylates have the structure... 

Esters of ether carboxylic acids (propylated and/or ethoxylated) and fatty alcohols or ethoxylated fatty alcohols are described [40], prepared by esterification of the ether carboxylic acid and the alcohol with an acid catalyst like H2S04 or p-toluenesulfonic acid under vacuum and at a temperature of about 130°C. The purpose of these esters is to mainly use them in cremes and lotions with better conditioning and moisture controlling properties. 

FIG. 6 Influence of the temperature on the foaming properties of an alkyl ether carboxylate compared to an alcohol ethoxylate. 0.1% solution, pH = 11. (From Refs. 61 and 64.)... 

Besides the use of anionics such as sulfonates and nonionics such as alkyl-phenol ethoxylates, in 1977 the use of ether carboxylates was also described [183] in terms of its excellent temperature, electrolyte, and hard water stability and low interfacial tension, especially in case of the C12-C14 ether carboxylic acid with 4.5 mol EO. 

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. 

There are some means for synthesis of defined primary or secondary esters. Monoester salts of phosphoric acid, for instance, are prepared by addition of alcohol or ethoxylated alcohol, alkali fluoride, and pyrophosphoryl chloride (C12P0)20 in a molar ratio of 0.9-1.5 0.05-1 1.0 at -50 to +10°C and hydrolysis of the Cl-containing intermediates with base. Thus, 32.3 g (C12P0)20 was treated at -50°C with 23.9 g lauryl alcohol in the presence of 0.7 g KF and the mixture was slowly warmed to room temperature and hydrolyzed with H20 and 40% NaOH to give 83% sodium monolauryl phosphate. The monoester salts showed comparable or better washing and foaming efficiency than a commercial product [12]. 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

Me-ester sulfonation has to be carried out at relatively high temperatures as the initial reactions and the decomposition of intermediate products is relatively slow compared with sulfonation reaction rates for alkylbenzenes, primary alcohols, ethoxylated alcohols, and a-olefins. The required aging time for conversion of the intermediates to FAME sulfonation acid is long (about 45 min at 85°C). It is not possible to sulfonate Me-esters without an excess of S03. 

The phase inversion temperature (PIT) method is helpful when ethoxylated nonionic surfactants are used to obtain an oil-and-water emulsion. Heating the emulsion inverts it to a water-and-oil emulsion at a critical temperature. When the droplet size and interfacial tension reach a minimum, and upon cooling while stirring, it turns to a stable oil-and-water microemulsion form. " ... 

An interesting and potentially u.seful variant is deployment of thermoreversibility, a situation where the reaction occurs at relatively high temperature in a homogeneous phase, which becomes a two-pha.se system at lower temperatures, facilitating catalyst recovery. Here, tailored ligands have to be u.sed. Ethoxylated phosphines have been suggested by Jin, Fell, and co-workers (1996, 1997). 

Mixtures of aqueous emulsions of oil can be more effectively transported through pipelines if certain antifreeze formulations are added to the system. Stable oil-in-water emulsions for pipeline transmission by using 0.05% to 4% ethoxylated alkylphenol as an emulgator and a freezing-point depressant for water enable pipeline transmission at temperatures below the freezing point of water [736]. 

Several surfactants were studied in ambient-pressure foam tests, including alcohol ethoxylates, alcohol ethoxysulfates, alcohol ethoxyethylsulfonates, and alcohol ethoxyglycerylsuUbnates [210]. Surfactants that performed well in the 1-atm foaming experiment were also good foaming agents in site cell and core flood experiments performed in the presence of CO2 and reservoir fluids under realistic reservoir temperature and pressure conditions. 

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