Nonionic surfactants carboxylic acid esters and fatty alcohol amides

(1)Fatty acid carboxylates mainly include fatty acid glycerides and fatty acid polyethylene glycol esters.

Nonionic surfactantsNeither the monoester nor the diglyceryl stearate are pure product, but a mixture with different component ratios as process conditions change. Generally, it is produced by reacting fatty acids and glycerol by heating to 180~250C under the action of an alkaline catalyst. Its application properties include emulsification, dispersion, solubilization and wetting. In the food industry, it is commonly used as a release agent in baking products and as an emulsifier in preparing various cold drink products; in cosmetics, it is used as a base for creams; and as a lubricant and corrosion inhibitor in metal processing.

Similar to fatty acid glycerides. Fatty acid polyethylene glycol esters are also multi-component mixtures and contain unesterified polyethylene glycol:

The performance of fatty acid polyethylene glycol esters is related to the carbon chain of the fatty acid, but more importantly, the molecular weight of polyethylene glycol. Its use is mainly in the textile industry as an emulsifier when using oils:

(2) Sorbitan fatty acid ester Sorbitan ester Alcohol is formed by dehydration of sorbitol, which is a mixture of the following two compounds,

Sorbitol at 225~250℃An acid catalyst is used to esterify the fatty acid and the sorbitol generated in the reaction to produce fatty acid sorbitol. The product is a mixture of mono-, di- and tri-esters. The brand name is Emulsifier S series, which is insoluble in water, but soluble in many mineral and vegetable oils. It is a water/oil type emulsifier. Mainly used in fiber, pesticides, food, cosmetics, and as emulsifier in petrochemical industry.

(3) Nonionic surfactantNatural oil polyoxygen The dominant vinyl ether in this category of products is castor oil polyoxyethylene ether, with the brand name emulsifier EL series. It uses castor oil as raw material, and it is made by the ethoxylation reaction between the hydroxyl groups contained in castor oil and ethylene oxide. The main purpose is to prepare textile oils and oil emulsifiers.

Fatty alcohol amides

When fatty acids and ethanolamine or diethanolamine are heated to 180°C, an amidation reaction occurs. The most important in this series of products are fatty alcohol amides reacted with fatty acids and diethanolamine.

The reaction between fatty acid and diethanolamine is relatively complex. In addition to the acid amine, it also produces ester. The ester will also be converted into an amide with excess monoethanolamine through some intermediate products or directly. The remaining diethanolamine will also automatically react with fatty acids to form salts during the reaction.

Due to the complexity of this reaction, the product is a multi-component mixture and changes with the molecular ratio of fatty acid to diethanolamine and the reaction conditions. Industrially, there are two types of fatty alcohol amides, namely 2:1 alcohol amides and 1:1 alcohol amides. The former is made by heating 1 m of fatty acid and 2 mol of diethanolamine at 160 to 180°C for 2 to 4 hours; the latter is made by using an equivalent ratio. The fatty acid methanol and diethanolamine are heated at 100-110°C for 4 hours, and the methanol is evaporated to obtain the product. The purity of 1:1 alcohol amide is very high, so it is also called ultra-pure alcohol amide. Fatty alcohol amides are characterized by foam stabilization and good washing performance. In addition, they can also increase the viscosity of liquid detergents. Its most commonly used uses are in the preparation of liquid detergents, various shampoos, dry cleaning agents and in the textile and leather industry. Detergents, etc. are also commonly used in compound metal cleaning agents.

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