설명(영) |
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This large group of amphoteric materials exhibits the structure:
where X may be hydrogen or -CH2COO-Na+ and where Y may be -CH2CO O-Na+ or -CH2CH2COO-Na+, or -CH2CHOHCH2SO3 -Na+, or -CH2CHOHCH2OPO3--H+Na+.
Occasionally the sodium ion is replaced by an alkanolamine cation, as in, e.g., DEA-Cocoamphodipropionate. If the pH is favorable, the amino nitrogen may be quaternized with an acidic substituent, such as -CH2COO-, to form a zwitterion. This diverse group of materials is prepared by reacting Fatty Acid derivatives with hydroxyethyl ethylenediamine; this yields a substituted imidazoline which is subsequently split during the reaction with, e.g., chloroacetic acid to yield an amphoteric compound such as Disodium Capryloamphodiacetate. The commercially available compounds in this class are fairly complicated mixtures of chemically related materials.
The Alkylamido Alkylamines are mild detergents which leave the hair conditioned after shampooing. They find wide use in baby shampoos and other rinse-off hair products because of their mildness and substantivity. |