Alcohol sulfates applications

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. 

As the length of the side chain increases the CMC decreases. The general rule for ionic surfactants is applicable to alcohol sulfates. This rule establishes... 

The applications of alcohol sulfates in consumer products depend on the alkyl chain and in some cases on the cation. Alcohol sulfates with alkyl chains 8 C1() are seldom used in consumer products except occasionally as hydrotropes in liquid detergent formulations. However, alcohol sulfates in the range C10-C18 are used in many commonly used formulations although other surfactants are generally added to enhance their properties. In some of these applications, particularly in shampoos, they compete with alcohol ether sulfates of the same alkyl chain distribution. The pattern of use of alcohol sulfates or alcohol ether sulfates in formulations varies with consumer personal care and laundry washing preferences in different cultural areas of the world. 

An important application of some sodium alcohol sulfates, particularly those based on C12 and C12-CI4 and produced in powder and needle forms, is as the basic surfactant ingredient in toothpastes. Sodium and triethanolamine lauryl sulfates are also components of shaving creams. 

In polymer applications derivatives of oils and fats, such as epoxides, polyols and dimerizations products based on unsaturated fatty acids, are used as plastic additives or components for composites or polymers like polyamides and polyurethanes. In the lubricant sector oleochemically-based fatty acid esters have proved to be powerful alternatives to conventional mineral oil products. For home and personal care applications a wide range of products, such as surfactants, emulsifiers, emollients and waxes, based on vegetable oil derivatives has provided extraordinary performance benefits to the end-customer. Selected products, such as the anionic surfactant fatty alcohol sulfate have been investigated thoroughly with regard to their environmental impact compared with petrochemical based products by life-cycle analysis. Other product examples include carbohydrate-based surfactants as well as oleochemical based emulsifiers, waxes and emollients. 

Alcohol sulfates (R — 0S03"Na ) - alcohol reacted with suihir trioxide then neutralized with sodium hydroxide. Applications include shampoo, bar soaps, and other personal care products laundry and dishwashing soap textiles and additives to emulsion polymerization. 

Water-insoluble PEC were prepared by mixing oppositely charged polyelectrolytes, e.g. DEAE dextran with CMD [340,341], sodium dextran sulfate, poly(styrene sulfonate) (NaSS) [342], poly(sodium L-glutamate) (PSLG), poly(vinyl alcohol)sulfate [343], or potassium metaphosphate (MPK) [240]. They are useful as membranes or in biomedical applications [343,344]. 

Field Application. The micellar-polymer process for enhanced oil recovery has been used in many field trials. Petroleum sulfonates are the most commonly used surfactant 41, 42). Other surfactants have been used, such as ethoxylated alcohol sulfates 43) and nonionic surfactants mixed with petroleum sulfonates 44). 

The chromatographic separation of fatty alcohol sulfates requires the application of the gradient technique. The retention of these compounds increases exponentially with the alkyl chain length. Fatty alcohol sulfates such as lauryl sulfate are constituents of... 

Besides the effects on detergency the liquid crystalline phases of surfactant systems at higher concentrations are of crucial importance for the processing of concentrated surfactant systems and the formulation, as well as the application, of liquid products. This will be demonstrated with the help of the phase diagram of anionic surfactants for the example of fatty alcohol sulfates. Figure 3.33 shows the complete phase diagram... 

Alkanolamides are similar to amine oxides in that their principal application is as foam stabilizers (boosters) in hand dishwashing formulations. Alkanolamides, however, are generally preferred in linear alkylben-zene sulfonate/alcohol-ether-sulfate-based formulations, while amine oxides seem to be the preferred foam stabilizer for alcohol sulfate/alcohol-ether-sulfate-based formulations. 

As one looks over the plethora of fatty surfactants available in the maiket today, one is overwhelmed with the possibilities. One may ask, why are there so many classes of surfactants available The answer clearly is that the different classes of surfactants function in different applications. For example, fatty quats are generally used for softening and conditioning fatty alcohol sulfates for detergency. It would be very difficult for a formulator to develop products, which have all the properties using only one class of fatty compounds. 

Alkyl sulfates or primary alcohol sulfates (PAS), which were the first synthetic surfactants used in personal care in the United States, are mainly used in toothpaste formulations. As for the AES, the alkyl moiety is typically a mixture of Ci2-Cjg chains. According to the application, one can find sodium, ammonium, magnesium, or triethanolamine salts of fatty alcohol sulfuric acid. They are obtained by the sulfation of a fatty (natural or synthetic) primary alcohol with a mixture of air/SOj according to the following reaction ... 

These surfactant classes are a subset of those used in cleaning applications, and there are classes that are noticeably absent from the list above, such as alcohol sulfates, salts of fatty acids (soaps), alkanolamides, aliphatic sulfonates, betaines (amphoterics), methyl ester sulfonates and the relatively new alkyl polyglycosides. All of these have seen various applications in the petroleum industry, but perhaps lesser importance in EOR. Cost, availability and performance are the obvious issues in determining the potential use of surfactants in EOR. 

Primary Applications are for use as intermediates in surfactants, plasticizers, lubricant additives, thioesters and other specialty chemicals. Typical surfactant derivatives include alcohol ethoxylates, alcohol sulfates and alcohol ether sulfates. EPAL fatty alcohols are also used as aluminum rolling lubricants, emollients and for other specialty applications. 

By far, the greatest application of fatty alcohol is in the manufacture of fatty alcohol sulfate and fatty alcohol ether sulfate. These materials possess good foaming properties and ready biodegradability and are extensively used as base surfactants for laundry detergent products, shampoos, dishwashing liquids, and cleaners. 

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