Shampoos amphoteric surfactants

Many of the surfactants made from ethyleneamines contain the imidazoline stmcture or are prepared through an imidazoline intermediate. Various 2-alkyl-imidazolines and their salts prepared mainly from EDA or monoethoxylated EDA are reported to have good foaming properties (292—295). Ethyleneamine-based imida zolines are also important intermediates for surfactants used in shampoos by virtue of their mildness and good foaming characteristics. 2- Alkyl imidazolines made from DETA or monoethoxylated EDA and fatty acids or their methyl esters are the principal commercial intermediates (296—298). They are converted into shampoo surfactants commonly by reaction with one or two moles of sodium chloroacetate to yield amphoteric surfactants (299—301). The ease with which the imidazoline intermediates are hydrolyzed leads to arnidoamine-type stmctures when these derivatives are prepared under aqueous alkaline conditions. However, reaction of the imidazoline under anhydrous conditions with acryflc acid [79-10-7] to make salt-free, amphoteric products, leaves the imidazoline stmcture essentially intact. Certain polyamine derivatives also function as water-in-oil or od-in-water emulsifiers. These include the products of a reaction between DETA, TETA, or TEPA and fatty acids (302) or oxidized hydrocarbon wax (303). The amidoamine made from lauric acid [143-07-7] and DETA mono- and bis(2-ethylhexyl) phosphate is a very effective water-in-od emulsifier (304). 

Amphoteric surfactants are those that are an acid and a base at the same time (like water is). Cocamidopropyl betaine, for example, is used in shampoos to stabilize foam and thicken the mixture. 

Cocamidopropyl betaine (Table 1.4) is the most prominent representative of the class of amphoteric surfactants. Due to the synergism with other surfactants and its gentleness to the skin and mucous membranes, cocamidopropyl betaine performs well in shampoo and cosmetics where its dosage lies in the order of 1-5% [27]. 

Although these surfactants represent less than 1% of the U.S. production of surfactants, the market use is increasing dramatically because of their unique properties [353]. Of particular importance is the synergistic effect that amphoteric surfactants have when used in conjunction with other types of surfactants. The non-eye-stinging characteristic of these compounds has been responsible for the upsurge in the baby shampoo market over time [354,355]. 

Amphoteric surfactants are used in shampoos and can be used with alkalis for greasy surfaces as well as in acids for rusty surfaces. 

Over the years, optimized amphoacetates were developed that were intermediate between the 1 and 2-mol products. An effort was made to deliver more amphoteric surfactant and less by-products to the formulator. Most baby shampoos and body washes produced today are formulated with such optimized products, which are produced from an optimum ratio... 

Amphoteric surfactants. These compounds have the characteristics of both anionic detergents and cationic fabric softeners. They tend to work best at neutral pH, and are found in shampoos, skin cleaners, and carpet shampoos. They are very stable in strong acidic conditions and are favorably used with hydrofluoric acid. For example, compounds of alkyl-betain or alkylsulfobetaine type possess both anionic and cationic groups in the same molecule even in aqueous solution. These surfactants are rarely employed in laundry detergents because of their high costs [3, 4]. 

Cocamidopropyl betaine is the most commonly used amphoteric surfactant in shampoos, bath products, and other cosmetic products. It is popular because of its relatively low irritation potential. 

There is minimal absorption of anionic, nonionic, and amphoteric surfactants. Antidandruff shampoos may contain zinc pyridinethione and selenium... 

The change in charge with pH of amphoteric surfactants affects their properties, such as wetting, detergency, and foaming. Atthe i.e.p., the properties of amphoterics resemble those of nonionics very closely, but below and above the i.e.p. the properties shift towards those of cationic and anionic surfactants, respectively. Zwitterionic surfactants have excellent dermatological properties, and also exhibit low eye irritation consequently, they are frequently used in shampoos and other personal care products (e.g., cosmetics). 

The most important requirement for baby shampoos is minimal irritation to scalp, hair, skin, and, especially, eyes. These products are often formulated with levels of nonionic and amphoteric surfactants higher than those found in basic cleaning shampoos. 

Ampholyt [H lsAG] Glycinates betaines amphoteric surfactant for cosmetics, shampoos, detergents. 

Amphoterge . [Lonza] Amphoteric surfactants wetting agent and detergent for shampoos, cleansers, dishwashing textile softener. 

Mackam. [Mcln ] Amphoteric surfactants foaming agent conditioner, vise, buildo for shampoos, cleansers, industrial and dishwash formulations. 

Miranol . [Rhone-Poulenc Surf. Rhone-Poulenc France] Amphoteric surfactant blends det ent wetting ag it emulsifier, solubilizer, stabilizer for shampoos, pharmaceuticds, household... 

For shampoos, shaving foams and tooth pastes, high stability and definite foam structure is one of the main factors determining the commercial value of the product. In this connection, conventional shampoos include anionics (ammonium or triethanolamine salts of alkylsulphates mixed with alkylolamides of natural fatty acids, e.g. coconut oil acids, as well as amphoteric surfactants and hydrolysed proteins. Detailed patent data on the formulations are given in [80, 110] and other reviews. 

Baby shampoos (Table 5-4) and some light conditioning shampoos employ nonionic surfactants such as PEG-80 sorbitan laurate (or as low as 20 EOs) and amphoteric surfactants such as cocoamphocarboxyglycinate or cocoamidopropylhydroxysultaine to improve the mildness of anionic surfactants and at the same time to improve cleaning and lather performance. 

This class of surfactant includes those that cany both positive and negative diarges. Depending on the pH of the preparation, this group behaves as a cationic, anionic, or nonionic species. In the cosmetics held, these surfactants are frequently applied in skin or hair formulations as relatively mild detergents. They are also used for their capacity for reducing the irritation of anionic surfactants. These surfactants are commonly accepted to be noninitant to the eyes and have consequently been used in baby shampoos. Amphoteric surfactants are very much used in cosmetics, but they are not found in the different pharmacopoeia studied here. 

As shown in Figure 22.1, 7% of total surfactants are used in cosmetics and pharmaceuticals, especially in personal care products such as shampoos, bath preparations or toothpastes. Surfactants are important in their function as emulsifiers in creams and lotions. A great variety of anionic, nonionic, cationic and also amphoteric surfactants are used here. 

The formulation class (tooth paste, shampoo, fabric softener, etc.) provides basic information about the components present. Standard shampoo formulations contain two types of surfactants (either two anionic or one anionic and one amphoteric surfactant) foam booster (nonionic surfactant) conditioner, viscosity improver, opacifier, dye, perfume, chelate, and preservatives. Normally, formulated products are available as liquid, solid, emulsion, dispersion, etc, with a great number of components (in some cosmetic products there may be 20 components) and some of them, such as the preservatives, are found at low concentrations. 

The surfactants used in a shampoo will be selected on the basis of several criteria such as detergency, foam volume and texture, irritation, cost, compatibility with other ingredients, color, odor, purity, and biodegradability. Usually, primary surfactants used in shampoos are anionic and inexpensive. They may be combined with secondary surfactants, such as nonionic or amphoteric surfactants (Table 6.7). 

Amphoteric surfactants are finding increased use in shampoo formulations because of several benefits that are consumer perceivable. Amphoteric surfactants in general are known to be poor foamers when used alone,and milder than traditional primary surfactants. Their use therefore is in many baby shampoos that often consist entirely of them, and also they are often incorporated in formulations to mitigate the effects of harsher primary surfactants. " Amphoteric surfactants also maintain their compatibility with all anionic, cationic, and nonionic surfactants over a wide pH range. Combination of these surfactants with other anionic surfactants provides decreased irritancy of a formulation while increasing the active content level of the product and therefore the quality of the lather produced. 

Amphoteric surfactants are divided into two groups based on their response to pH. One class of compounds that contain carboxylated imidazoles and A-alkyl betaines are zwitterionic at pHs at, and above, their isoelectric points and cationic at lower pHs. Sulfobetaines and phosphobetaines, on the other hand, exhibit zwitterionic characteristics as the anionic portion is dissociated at all pHs. Although the former are the major ingredients in many baby shampoos or those products that provide mildness, they also function as foam and viscosity enhancers when utilized as secondary surfactants, having good water solubility over a wide pH range. ° ... 

Amphoterics are excellent foamers and foam stabilizers under a variety of conditions. Their foamability is essentially insensitive to water hardness. Capitalizing on these properties, amphoterics were among the many specialty surfactants commercialized after World War II [2]. Since then, these surfactants have been used in personal care products because of their unsurpassed mildness and low eye-sting properties. Today, most mild skin cleansers and shampoos contain an amphoteric surfactant as a major component. 

The market launch of the Johnson Johnson No More Tears shampoo containing Miranol s amphoteric surfactant in the early 1960s proved to be the beginning of worldwide use of these... 

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