Ether sulfate shampoos

Marini et al. Lauryl ether sulfate Shampoo Titration/ion... 

Carolei and Gutz (2005) Lauryl ether sulfate Shampoo Uquid soap FTIR-ATR... 

Shampoos based on lauryl sulfates can range from 6—17% of the active surfactant. However, though they are effective cleansers, the alkyl sulfates tend to be defatting. In an effort to make these shampoos more mild, many shampoos are now based on blends of amphoterics and alkyl sulfates or the less irritating alkyl ether sulfates. 

The most common ingredient in shampoos is also the most common detergent in use in other products a class of surfactants known as straight-chain alkyl benzene sulfonates. Examples are ammonium lauryl sulfate, its sodium relative, and the slightly larger but related molecule ammonium lauryl ether sulfate (sometimes abbreviated as ammonium laureth sulfate). 

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. 

Sodium alcohol sulfates have a limited solubility compared to sodium alcohol ether sulfates and are more suitable for cream, pearlized, and paste shampoos. Alcohol sulfates are more frequently used in general shampoo formulations in the United States than in Europe. Europe has moved toward alcohol ether sulfates for historical and traditional reasons, different availability of ethylene oxide, and possibly other technical reasons such as the more favorable dermatological properties of alcohol ether sulfates and their better behavior in hard waters. Triethanolamine alcohol sulfates are widely used in shampoos because of their comparatively high solubility in water, good foaming properties, and low irritancy. 

Contact of surfactants with the skin and mucus membranes occurs either accidentally or as a consequence of normal use. Examples of this normal and everyday use are cleaning formulations, shampoos, foam baths, and toothpastes. Again this contact is seldom made with individual surfactants, in this case alcohol sulfates and alcohol ether sulfates, but through formulated products. It is known that surfactants present significant interactions, so that mixed systems are generally less aggressive than their individual components. However, the effect of pure surfactants merits attention, particularly sodium dodecyl sulfate, which is commonly used as a reference for many studies because of its high purity and availability. 

Until the 1950s ether carboxylates were almost in very limited amounts in the textile industry. It was only in 1957 [9] that the first ethercarobxylates were mentioned, in combination with other surfactants such as alkyl sulfates and ether sulfates, for use in shampoos. In spite of the special properties of ether carboxylates, their use was low in the industry as well as in cosmetics at that time. This was also due to the fact that at that time properties such as toxicity, biodegradability, and mildness to the skin did not have the high priority they do now. 

These higher foaming properties are very useful for such cosmetic formulations as shampoos, showerbaths, and so on. This is the same with the forming of fine bubbles and the improving of foam stability of other surfactants such as, for example, alkyl ether sulfates due to the combination with ether carboxylates [57,67-69] (Table 9). 

Although by 1957 [9] the use of ether carboxylates also in combination with other surfactants such as alkyl ether sulfates for shampoos had been described,... 

In combination with alkyl ether sulfates, a synergistic decrease of the irritation level of the ether sulfates and an improvement of the foam stabilization has been described [57,67,78]. A good compromise between mildness and foam properties could be achieved with lauryl ether carboxylic acid sodium salt with 10 mol EO [57,67]. In several articles examples of the use of alkyl ether carboxylates as cosurfactant in mild shampoos as well as bath and shower products have been described [57,69,79]. 

All of the aspects and applications described in papers can be traced back to the patent literature [73]. The special or synergistic effect of ether carboxylates in combination with other surfactants is very often the basis, like combinations with alkyl ether sulfates or alkyl sulfates, for shampoos, foambaths, showerbaths, and liquid soaps [9,70,81-85], and the same for amidether carboxylates [71]. 

Alkyl Ether Sulfates (AES) R=Cio C14 m=l-4 Liquid bath soaps, hair shampoos, and mechanical dishwashing agents. Ingredient in industrial cleaning agents - Effluents of seven representative STPs Cl2-15 AES 3 and 12 pg L 1 [15] Readily biodegradable in WWTPs under both aerobic and anaerobic conditions [18,29]... 

Alcohol ether sulfates (R0(CH2CH20)S03"Na-") - alcohol ethoxy-late reacted with sulfur trioxide and then neutralized in NaOH. Application s include dishwashing liquids and shampoos, home laundry powders, and personal care products. 

Cosmetic Rinse off Preparations. In certain cosmetic products, tor example hair shampoos, it is not possible to use complexing agents because of the irritation of mucous membranes. Here a low sensitivity of surfactants to water hardness is a precondition for their application. Foam formation is generally considered to be a measure of shampoo quality (Table V). With increase in water hardness the foam volume of alkyl sulfates decreases very much, whereas with the corresponding alkyl ether sulfates this decrease is relatively small. For cosmetic applications, the good skin compatibility and low irritation to mucous membranes of alkyl ether sulfates is of high importance (37). 

Alkyl Ether Sulfates. These surfactants are also found in shampoo applications. They are prepared similady to alkyl sulfates except that the fatty alcohol is... 

The ether sulfates are used in light-duty liquids, heavy-duty powders, and shampoos. 

These alkyl dimethyl amine oxides are used as foam stabilizers primarily in light-duty liquids and shampoos where the major active ingredient is either an alcohol ether sulfate or an alcohol sulfate. The alkyl group is usually C19 to C.. which gives the best overall foam stability (3). 12 14... 

Shampoos. Ether sulfates are extensively used in shampoo formulations in the range of 15 to 25 percent active. The general product of choice is the lauryl-range alcohol with 1 to 3 moles of ethylene oxide. In shampoos, either sodium, ammonium, or triethanolamine salts of the ether sulfate can be used. The choice of these products will be primarily related to the solubility and the finished form of the shampoo. Triethanolamine salts are considerably more soluble and, thus, will be found in a large number... 

As mentioned earlier, the amine oxides are used in dishwashing liquids and in shampoos where the major surfactant is either an alcohol ether sulfate or an alcohol sulfate. 

By far, the greatest apphcation 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. 

Fatty Alcohol Ether Sulfates. Probably the most important derivatives of fatty alcohol in the C12-C14 and C12-C16 ranges are the fatty alcohol ether sulfates. They are produced by the sulfation of the fatty alcohol, containing 2-3 moles of ethylene oxide, with sulfur trioxide or chlorosulfonic acid and subsequently neutralized with caustic soda, ammonia, or an alkanolamine. The ether sulfates possess superior properties over the fatty alcohol sulfates. They have unlimited water solubility, are unaffected by water hardness, and possess superior skin compatibility. Accordingly, they are used in liquid shampoos and bath preparations. One characteristic of this material is its ability to increase its viscosity by the addition of an electrolyte such as salt (5). 

Other coco-based surfactants are sulfosuccinates formed by the reaction of coco fatty alcohol with maleic anhydride and further reaction with sodium sulfite or bisulfite. This product possesses good foaming properties, is compatible with soap, and is a good lime dispersant. It is used in toilet soap formulation, shampoos, hand cleaning pastes, and for scouring raw wool. Its ether variant, with 2-4 moles ethylene oxide, forms intense, finely structured foam and is used in combination with ether sulfate in baby shampoos and bath preparations. 

Salts, generally sodium but also triethanolammonium, of long-chain alcohol sulfates and alcohol ether sulfates are the most widely used surfactants in shampoo formulations. Alkanolamides act as viscosity regulators and foam stabilizers. 

As mentioned in Section II.A.l(a), the presence of ethylene oxide moieties in alkyl ether sulfates reduces surfactant irritation. Polysorbate 20 and PEG-80, which have 20 and 80 moles of ethylene oxides, respectively, are often incorporated into baby shampoos as anti-irritants. Magnesium salts of these surfactants are also milder than the sodium salts. Table 10.8 shows an example of the formulation of a mild baby shampoo from U.S. Patent 3,928,251. More developments in mild and nonirritating shampoo formulas are listed in Table 10.9. 

Nissan Sunamide. [Nippon Oils ft Fats] Fatty alkylolamide ether sulfate base for shampoos and dishwashing detergents. 

Other soils have not been studied so extensively however, Robbins et al. [29] have shown that Cn alkyl sulfates or alkyl ether sulfates, the traditional shampoo surfactants, do not remove cationic surfactants from hair effectively under certain conditions. However, shorter chain-length anionics such as deceth-2 sulfate is more effective for removing cationics. In addition, alkyl ether sulfates are more effective for removing fatty acid soils in the presence of water hardness than alkyl sulfates [29]. 

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