Anionic surfactant is a kind of product with the longest history, the largest output and the most varieties among surfactants. According to the structure of hydrophilic groups, anionic surfactants can be divided into sulfonates and sulfates, which are the main categories of anionic surfactants.
The anionic surfactants definition is a must-known concept for many people working in the chemical industry. The various functions of surfactants are mainly manifested in changing the properties of the liquid surface, liquid-liquid interface and liquid-solid interface, of which the surface (interface) of the liquid is the most important.
Sulfate-type anionic surfactants mainly include fatty alcohol sulfate (also known as primary alkyl sulfate) and secondary alkyl sulfate：
1. Fatty alcohol sulfate (ester) salt (FAS or AS). The general formula of fatty alcohol sulfate is: ROS0-3M+, R is alkyl, M+ is sodium, potassium, ammonium, ethanolamine and other cations, also known as primary alkyl sulfuric acid Salt, English abbreviated as FAS or AS.
It is the earliest anionic surfactant after soap. It is prepared by esterification of c12-c14 fatty alcohols generated by Hydrogenolysis of coconut oil with sulfuric acid and neutralization. It has suitable solubility, foaming and decontamination properties. It is widely used in dentifrice, shampoo, bubble bath and cosmetics. It is also an important component in the formulation of light scale, heavy scale detergents, carpet cleaners and hard surface cleaning agents, such as sodium lauryl sulfate (C12H25OSO3Na).
2. Secondary alkyl sulfate (Teep01). It is a secondary alkyl sulfate produced by the reaction of olefin and sulfuric acid. It is a product obtained after neutralization. The trade name is Teep01. Teep01, similar to FAS, is also a kind of surfactant agent with good performance, but its solubility and wettability are better due to structural differences. It is usually made into liquid or slurry detergent, since the powder product is easy to absorb moisture and agglomerate.