Amphoteric surfactants amphoacetates

The foam-holding characteristics of foam from surfactants in oil field jobs can be tailored by adding an imidazoline-based amphoacetate surfactant. Amphoacetates are a special class of amphoteric tensides (Figure 16-1). Imidazoles, such as 2-heptylimidazoline, are reacted with fatty acids under the ring opening. For alkylation, the imidazoline is reacted with, for example, chloroacetate [493]. 

Two major classes of amphoteric surfactants are derived from fatty alkyl hydroxyethyl imidazolines which, in turn, are produced from fatty acids and low molecular weight amines. Because fatty acids are fairly economic, the imidazoline derived amphoacetates tend to be less expensive than the iminodipropionates discussed above. Most imidazoline derived... 

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... 

Cationic and nonionic surfactants are not very common for bar products. However, they can be used at very low levels for certain functional properties. Anionic and amphoteric surfactants are more cost-effective, and have balanced mildness with excellent lathering properties. Some of the nonionic surfactants such as sugar esters and amphoacetates have very good mildness and lathering properties, but are not cost-effective. These surfactants are suitable mainly for liquid products. In combination with fatty acid soaps, SCI, suUbsuccinate, AGES, AOS, and CMGS have been used as surfactants in syndet and combars. 

Amphoteric surfactants comprise a broad range of compounds, which display nonionic, cationic, or even anionic tendencies depending on pH or in-use conditions. Betaines, imadazoline-derived amphoacetates, alkylamino propionates, and glycinates are generally included in this category. Amine oxides, which may exhibit nonionic or cationic characteristics depending on pH conditions, are also included in this category. 

These surfactants are well established as extremely mild surfactants [7]. They are referenced in the CTFA dictionary as sodium coco (or lauryl) amphoacetate and disodium coco (or lauryl) amphodi-acetate. Amphoterics are widely used in mild, tear-free shampoos and sensitive skin cleansers due to their favorable surfactant properties, low irritation profile, and irritation-mollifying properties [8], Amphoacetates or diacetates are excellent foaming agents, even in hard water, and they exhibit compatibility with all other types of surfactants. 

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