Cocamidopropyl Betaine

Brief Overview

Cocamidopropyl betaine, also known as coco amido propyl betaine and CAPB, is a coconut-derived, sticky, yellow liquid with a slightly "fatty" odor. The name reflects the fact that the molecule's major component, the lauric acid group, is derived from coconut oil. Cocamidopropyl betaine has largely supplanted cocamide DEA.

Manufacturing process

Despite the name cocamidopropyl betaine, the molecule is not synthesized from betaine. Instead it is produced in a two step manner, beginning with the reaction of dimethylaminopropylamine (DMAPA) with fatty acids from coconut or palm kernel oil (lauric acid, or its methyl ester, is the main constituent). The primary amine in DMAPA is more reactive than the tertiary amine, leading to its selective addition to form an amide. In the second step chloroacetic acid reacts with the remaining tertiary amine to form a quaternary ammonium center (a quaternization reaction).[3]

CH₃(CH₂)10COOH + H₂NCH₂C_H2CH₂N(CH₃)₂ → CH₃(CH₂)10CONHCH₂CH₂CH₂N(CH₃)2
CH₃(CH₂)10CONHCH₂CH₂CH₂N(CH₃)2 + ClCH₂CO2H + NaOH → CH₃(CH₂)10CONHCH₂CH₂CH₂N+(CH₃)2CH₂CO₂− + NaCl + H₂O

Detergent Industry

Many detergents are drying to hair or skin. Cocamidopropyl betaine contains coconut oil, which is hydrating. It's less drying than other surfactants. Cocamidopropyl betaine reduces the drying effects of harsher detergents in skin and hair care products. Personal Care Industry From shampoo to soaps, toothpaste, shaving cream, makeup removers, body wash, detergents, and cleaners, cocamidopropyl betaine is most typically used to create rich, thick lather in foaming products. Pharmaceutical Industry The foaming and thickening property are used to create stable solutions of pharmaceutical products. Furthermore, the chemical is stable under acidic and alkaline solutions. The chemical also has conditioning properties and compatible with other surfactants.