Sulfated alcohol

L stoichiometric reactions expensive produces HCl gas, disposal alcohol sulfation, dye 5, etc... 

Anhydrous sulfonic acids, particularly linear alkylben2enesulfonic acids, are typically stored ia stainless steel containers, preferably type 304 or 316 stainless steel. Use of other metals, such as mild steel, contaminates the acid with iron (qv), causiag a darkening of the acid over time (27). The materials are usually viscous oils which may be stored and handled at 30—35°C for up to two months (27). AH other detergent-grade sulfonic acids, eg, alcohol sulfates, alcohol ether sulfates, alpha-olefin sulfonates, and alpha-sulfomethyl esters, are not stored owiag to iastabiUty. These are neutrali2ed to the desired salt. 

The adsorbed layer at G—L or S—L surfaces ia practical surfactant systems may have a complex composition. The adsorbed molecules or ions may be close-packed forming almost a condensed film with solvent molecules virtually excluded from the surface, or widely spaced and behave somewhat like a two-dimensional gas. The adsorbed film may be multilayer rather than monolayer. Counterions are sometimes present with the surfactant ia the adsorbed layer. Mixed moaolayers are known that iavolve molecular complexes, eg, oae-to-oae complexes of fatty alcohol sulfates with fatty alcohols (10), as well as complexes betweea fatty acids and fatty acid soaps (11). Competitive or preferential adsorption between multiple solutes at G—L and L—L iaterfaces is an important effect ia foaming, foam stabiLizatioa, and defoaming (see Defoamers). 

Ethoxylated alcohol sulfates have several advantages over alcohol sulfates including lower sensitivity to hardness with respect to foaming and detersive effectiveness, less irritation to skin and eyes, and higher water solubiUty. 

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. 

In 1932 the first household detergent based on synthetic surfactants was brought into the market under the name FEWA (Feinwaschmittel). The product was produced from fatty alcohol sulfate by Bohme Fettchemie in Chemnitz. The shortage of the necessary natural raw materials caused by World War II led to the development of products based on more readily available raw materials [2],... 

It has been reported that the LAS/AS mixed active system was produced by continuous oleum sulfonation of LAB followed by addition of the alcohol and more oleum to provide a tandem sulfation [40]. Tallow range alcohol sulfate (Ci6-is AS) was used in the past when U.S. wash temperatures were as high as 60°C. At these wash temperatures and in phosphate-built formulations the Ci6 18 AS gave very good detergency performance [41]. However, as U.S. washing temperatures decreased, C16.,8 AS was replaced by the more soluble shorter-chain ASs, such as C12.I8 or C,4, 5. 

APG, alkyl polyglucoside FAA, fatty acid alkanolamide FAEO, fatty alcohol ethoxylate FAES, fatty alcohol ether sulfate FAGA, fatty acid glucamide FAS, fatty alcohol sulfate LAS, linear alkylbenzenesulfonate SAS, secondary alkanesulfonate. 

V. Analysis of Alcohol Sulfates and Alcohol Ether Sulfates 278... 

Primary alcohol sulfates are half esters of sulfuric acid. These substances are relatively simple organic molecules and have been known for a long time. The first alcohol sulfate was prepared by Dumas in 1836 [1] but long-chain alcohol sulfates were not used as surfactants until the 1930s [2]. 

Alcohol sulfates were first obtained either by the reaction of olefins with sulfuric acid or by sulfation of alcohols produced by hydrogenolysis of oils and fats with sulfuric acid. With the advent of petrochemistry and the progress of chemistry and chemical engineering, alcohol sulfates and their derivatives have become one of the most important surfactants and are produced in large amounts using techniques different from those originally used. They are based on a wide range of alcohols and have found applications in almost all domestic and industrial sectors. 

As esters of sulfuric acid, the hydrophilic group of alcohol sulfates and alcohol ether sulfates is the sulfate ion, which is linked to the hydrophobic tail through a C-O-S bond. This bond gives the molecule a relative instability as this linkage is prone to hydrolysis in acidic media. This establishes a basic difference from other key anionic surfactants such as alkyl and alkylbenzene-sulfonates, which have a C-S bond, completely stable in all normal conditions of use. The chemical structure of these sulfate molecules partially limits their conditions of use and their application areas but nevertheless they are found undoubtedly in the widest range of application types among anionic surfactants. 

Alcohol sulfates can also be obtained by treatment of olefins with sulfuric acid but this method has never achieved a significant industrial importance and is now abandoned. 

The reaction of olefin sulfation and its possibilities has been extensively studied [3-10] and it was used to produce alcohol sulfates. Dry distillation of spermaceti gives palmitic acid and cetene-1, which can be sulfated with sulfuric acid to give cetyl-2 sulfate [11]. Other surfactants were obtained from olefins produced from natural substances, such as alcohol sulfates by sulfation of olefins from decarboxylation of oleic acid [12], by sulfation of olefins made by dehydrating hydroabietyl alcohol, by direct sulfation of abietyl alcohol [13,14], or by sulfation of natural terpenes [15]. 

The production of alcohol sulfates from fatty alcohols was firstly performed with concentrated sulfuric acid used in molar excess. The reaction is reversible ... 

Years ago sulfation with chlorosulfonic acid was the most significant industrial method to obtain alcohol sulfates because it offers multiple advantages over sulfation with sulfuric acid. The reaction proceeds with evolution of hydrogen chloride as follows ... 

A published account of laboratory batch sulfations of Alfol 1214 SP, Alfol 1216 SP, and natural coconut alcohol using chlorosulfonic acid at atmospheric pressure and 16 L/min dry air sparged through the reaction mixture to remove HC1 is available [42], The optimal conditions and the characteristics of the triethanolamine alcohol sulfates obtained are shown in Table 1. 

Sulfur trioxide converts alcohols to acid alcohol sulfates directly [Eq. (1)]. It is thought that sulfur trioxide reacts with the hydroxyl group forming firstly an alkyl hydrogen pyrosulfate which decomposes to alkyl hydrogen sulfate. The first reaction ... 

Alcohol sulfates are half esters of sulfuric acid and contain a C-O-S bond in the molecule. This bond is only relatively stable in water and can hydrolyze, mainly under acidic conditions. The hydrolysis is favored by temperature as was proven in the study of Maurer et al. with octadecyl sulfuric acid [57]. They found that a 0.05 M solution in distilled water at 100°C hydrolyzed to 50% in less than 30 min, whereas at 60°C the hydrolysis was 10% after 3 h and 16% after 7 h. 

The hydrolysis of 0.05 N surfactant solutions was carried out in 0.05 N HC1 solution at 80°C. These constants demonstrate that propoxylated sulfates are less stable than those ethoxylated and all them less stable than alcohol sulfates. The time for 50% hydrolysis was 92 min for sodium hexadecyl ether (1 PrO) sulfate, 98 min for sodium octadecyl ether (1 PrO) sulfate, 136 min for sodium octadecyl ether (1 EO) sulfate, and 187 min for sodium hexadecyl sulfate... 

Triethanolamine salts of alcohol sulfates form white crystals when obtained in pure form after recrystallization. At their melting point they are semisolid with gelatinous appearance and the transition is difficult to detect. Melting points, determined through thermograms obtained by differential scanning calorimetry, gave 72, 76, 80, and 86°C for dodecyl, tetradecyl, hexadecyl, and octadecyl sulfates, respectively [63]. 

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