Surfactants provide a good cleaning power and rich foam for shampoo, so that shampoo has an excellent cleaning effect. The surfactants used for shampoo are anions, non-ions, and amphoteric ions. Some
cationic surfactants can also be used as raw materials for washing, but the decontamination foam is still dominated by anions. Using their osmotic, emulsifying and dispersing effects, dirt is removed from hair and scalp.
Fat alcohol sulfate(AS) and fat alcohol polyoxyvinyl ether sulfate(AES): mostly sodium salt and amine salt, this type of
surfactant washing power is excellent, stable to hard water, foaming force meets the foam requirements of shampoo, It is the most commonly used ingredient in shampoo formulations.
AS has good foaming and decontamination power and good water solubility. Its aqueous solution is neutral and has resistance to hard water, but its solubility in water is not high enough and it is slightly irritating to the skin and eyes.
AES greatly improves its water solubility due to the addition of ethylene oxide. Even sodium salts have better solubility and hard water resistance, and the irritation to the skin is also reduced. Will reduce the bubbling force and washing ability. The number of ethylene oxide increased, the water solubility increased, and the consistency increased, but the turbidity decreased. The addition number of ethylene oxide is the most suitable for bubbling and washing power of 2-4 MOL.
In shampoo, it is usually used in combination with AES with better hydrophilicity and lower irritation, changing the length of the alkyl chain and polyethylene chain, moderately adjusting the bubbling, irritating and hydrophilic. In shampoos using AES, inorganic salts are generally used for thickening. Although AES bubbles rapidly, the foam is not stable enough. Therefore, it is also necessary to add stabilizer combinations, such as using alkyl amide to improve performance. The most commonly used AES is Laurel alcohol polyoxyvinyl ether (3EO) or (2EO) sodium sulfate, and fatty alcohol polyoxyvinyl ether triethanolamine sulfate.
Alpha-enyl sulfonate(AOS): Good decontamination and foaming properties in hard water, good biodegradation, low irritation to the skin, stable at low pH, and good compatibility with other surfactants.
