Fatty amines refer to a large class of organic amine compounds with carbon chain lengths ranging from C8 to C22. Like general amines, they are classified into primary, secondary, tertiary, and polyamines, depending on the number of hydrogen atoms in the amine group replaced by alkyl groups.
Fatty amines are organic derivatives of ammonia. Short-chain fatty amines with C8-10 have a certain solubility in water, while long-chain fatty amines are generally insoluble in water and are liquid or solid at room temperature. They are alkaline and have irritating and corrosive effects on the skin and mucous membranes. They are mainly produced by the reaction of fatty alcohols with dimethylamine, which generates single alkyl dimethyl tertiary amines; with methylamine, which generates double alkyl methyl secondary amines; and with ammonia, which generates triple alkyl tertiary amines. Firstly, the reaction of fatty acids with ammonia produces fatty nitriles, and then the hydrogenation of fatty nitriles produces fatty primary or secondary amines. Fatty primary or secondary amines can be methylated to produce tertiary amines. Primary amines can be converted into secondary amines by cyanomethylation, and then hydrogenation can generate secondary amines. Secondary amines can be converted into tertiary amines by cyanomethylation, and then hydrogenation can generate tertiary amines. Tertiary amines can be further converted into quaternary amines by cyanomethylation and hydrogenation.
Primary amines can be used as corrosion inhibitors, lubricants, release agents, oil additives, pigment processing additives, thickeners, wetting agents, fertilizer dust suppressants, engine oil additives, fertilizer anti-caking agents, mold release agents, flotation agents, gear lubricants, hydrophobic agents, waterproofing additives, wax emulsions, etc. Saturated high-carbon primary amines such as octadecylamine are used as hard rubber and polyurethane foam release agents. Dodecylamine is used in the regeneration of natural and synthetic rubber, as a surface-active agent in chemical tin plating solutions, and in the production of malt derivatives from reducing amine alkylation of isomaltose. Oleylamine is used as a diesel fuel additive, etc.
Production of Cationic Surfactants
Primary amines and their salts can be used as effective flotation agents for ores, anti-caking agents for fertilizers or explosives, waterproofing agents for paper, corrosion inhibitors, lubricating additives, bactericides for petroleum industry, fuel and gasoline additives, electronic cleaning agents, emulsifiers, production of organo-metallic clays, pigment processing additives, water treatment agents, and mold release agents. Primary amines can be used to produce quaternary ammonium salt-type bitumen emulsifiers, which are widely used in the construction and maintenance of high-grade highways, reducing construction and maintenance labor, and improving the service life of road surfaces.
Production of Nonionic Surfactants
Adducts of primary amines and ethylene oxide are mainly used as antistatic agents in the plastics industry. Ethoxylated amines cannot dissolve in plastics and migrate to the surface of the plastics. Once they reach the surface, ethoxylated amines absorb atmospheric moisture, and the surface of the plastics becomes antistatic.
Production of Amphiphilic Surfactants
N-Dodecyl-B-alanine is obtained from the reaction of dodecylamine and methyl acrylic acid, followed by saponification and neutralization. This type of surfactant has the following properties: the aqueous solution is a light or colorless transparent liquid, easily soluble in water or ethanol, biodegradable, resistant to hard water, and has low irritation and toxicity to the skin. Its uses include as a foaming agent, emulsifier, corrosion inhibitor, liquid detergent, shampoo, hair conditioner, fabric softener, and antistatic agent.