Shampoos cationic surfactants

Quaternary ammonium compounds are cationic surfactants that bind well to anionic surfaces like the protein in hair. The ammonium end sticks to the hair, leaving the long fatty end of the molecule to act as a lubricant. They are slightly conductive, so they reduce the buildup of static electricity. Quats, as they are sometimes called, include compounds like stearalkonium chloride, disteardimonium chloride, quaternium-5, or quaternium-18, polyquaternium-10 and they are all similar in form and function to cetrimonium chloride. These compounds are also widely used as fabric softeners, for all of the same reasons they make good hair conditioners. They are also used to thicken the shampoo. 

In a patent survey [76] about shampoos over the period 1968-1978 the so-called cryptoanionic alkyl ether carboxylate based on tridecyl alcohol with 6.5 mol EO has been mentioned for a conditioning shampoo in combination with an amphoteric and cationic surfactant [77]. Because of the low interference with cationic surfactants no negative effect on the conditioning properties has been found [78]. 

Cationic surfactants contain a positively charged headgroup and are typically used as conditioners to improve hair manageability and reduce static. Cationic surfactants are especially irritating to eyes when used in high concentrations but are safe and useful in low amounts. Quatemium-15 (chloroallyl methanamine chloride, Fig. 7.9.4) is a cationic surfactant included in shampoo formulations... 

Fatty Acid—Sarcosine Condensates. These surfactants are prepared by the reaction of fatty acid chlorides with methyl glycine sodium lauroyl sarcosinate [137-16-6] is an example of this group. They are most effective at pH 5.5—6.0 for foaming activity in soft to moderately hard water. The action of these deteigents is gready reduced under severe hard water conditions. The sarcosinates exhibit compatibility with cationic surfactants and have been suggested for use in formulation of conditioning shampoos (7). 

In acid solutions, the amino group is protonated and acts as a cationic surfactant, whereas in neutral or alkaline solution the amine oxides are essentially nonionic in character. Alkyl dimethyl amine oxides are water-soluble up to Cj, alkyl chain. Above pH 9, amine oxides are compatible with most anionics, but at pH 6.5 and below some anionics tend to interact and form precipitates. In combination with anionics, amine oxides can be used as foam boosters (e.g., in shampoos). 

Polymeric gums are also important compounds for building viscosity in shampoos and conditioners. They are easily dispersed in water at common use levels of 0.5 to 1.5%. The most commonly used cellulose polymer is hydroxyethycellu-lose, which is compatible with anionic and cationic surfactants and stable over a wide pH range [24], Other cellulose polymers in use include methylcellulose and hydroxypropylmethylcellulose. 

Autopur. fSschimmer Schwarz] Non-ionic/cationic surfactants basic material ftv car shampoos. 

Creme rinses and most hair conditioners are basically compositions containing cationic surfactant in combination with long chain fatty alcohol or other lipid components. Distearyldimonium chloride, cetrimonium chloride, stearalkonium chloride, and behentrimonium methosulfate are typical cationic surfactants used in many of today s hair conditioning products. Amines like dimethyl stearamine or stearamidopropyl dimethylamine are other functional cationics used in these products. Cationic polymers such as Polyquaternium-10 (quaternized ceUulosic) and Polyquatemium-7 (copolymer of diallyl dimethyl ammonium chloride and acrylamide) are also used (more in shampoos than in hair conditioners) however, care must be taken to avoid buildup on hair when formulating with cationic polymers. See the section on Cationic Polymers and Their Interactions with Hair in Chapter 7. 

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]. 

Creme rinses, on the other hand, are basically compositions containing cationic surfactant in combination with long-chain fatty alcohol or other lipid components. For additional details on product compositions, see the section of this chapter on formulations ( Structures, Formulation, Examples and Making Produces for Shampoo and Conditioning Ingredients ) and consult References 55-57, product ingredient labels, and the books by Hunting [4,5]. 

Soaps and surfactants, lipids, cationic ingredients, and even polymers or polymer association complexes have been used as conditioning ingredients in shampoos and/or conditioning products. Soaps deposit their hydrophobic salts on the hair or bind by metal bridging. Cationic surfactants and polymers attach substantively to hair by ionic bonds enhanced by Van der Waals attractive forces. The substantivity of most polymer association complexes is probably due to their hydrophobic nature, enhanced by Van der Waals forces (entropy) and possibly ionic bonds. 

Creme rinses are analogous to conditioning shampoos in causing hair effects chiefly by the adsorption of ingredients to hair. The primary active ingredient of most creme rinses is a cationic surfactant such as stearalko-nium chloride or cetrimonium chloride. 

The condition of the hair also affects the uptake and the diffusion of creme rinse and shampoo ingredients. A rule of thumb is that diffusion is faster into altered or damaged hair than into unaltered hair. Bleaching also lowers both the isoelectric and the isoionic points of hair, thereby attracting more cationic surfactant to the hair. Thus, the use of bridging agents is even more important to the adsorption to bleached hair than to chemically unaltered hair. 

Liquid water at room temperature can penetrate across the entire fiber in less than 15min and in less than 5min at 92°F [76], whereas more than 6h is required for single hbers to equilibrate in a humid atmosphere, and even longer for a hber assembly. Dyes like methylene blue (MW 320) and orange II (MW 350) generally require over an hour to penetrate through the cuticle layers to the cortex. Similar penetration times would be expected for typical anionic and cationic surfactants used in shampoos and hair conditioners. 

Toxicology TSCA listed Uses Antistat, emulsifier, surfactant in cosmetics superfatting agent in shampoos, hair care forms cationic surfactant, emulsifier, emollient with acids... 

As mentioned in Chapter 1, there can be thousands of molecules with polar heads and nonpolar tails, usable as surfactants. The applications are also many. Thus, the commercial anionic surfactants, recording about 50% of all surfactant production, are literally used all over the place shampoos, dishwashing detergents and washing powders are some common examples. Cationic surfactants likewise are used in hair-conditioners, fabric softeners, asphalt coating, corrosion inhibitor formulations for metal surfaces etc. The major applications of non-ionic surfactants are in the areas of food and drinks, as also pharmaceuticals and cosmetics. Amphoteric /zwitterionic surfactants have only limited applications one area is cosmetics, especially skin care products. 

Cationic surfactants also improve the wet and dry combing and reduce fly-away. However, they are incompatible with anionic surfactants and cannot be used in shampoo formulations. Cationic surfactants, which are mainly quaternary ammonium, are used in hair conditioners. They are called quats and can also be used to thicken the formulation (Table 6.11). 

In contrast to the benefits discussed above, cationic surfactants are generally incompatible with anionic surfactants, the primary surfactants used in shampoo formulations, which further limits their applications. The cleaning and foaming properties of cationic surfactants are considerably inferior to those of the anionics, and another major downside is the weighing-down effect on hair. Because of these limitations and compatibility issues, cationic surfactants are not used very often in shampoo formulations, and applications are limited mainly to conditioning, lubricating, and antistatic benefits in conditioners. 

Schoenberg TG, New looks at cationic surfactants for today s low pH shampoo. Cosmetic and Perfumery, 90, 89, 1975. 

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