octadecylamine

Octadecylamine, also known as octadecan-1-amine or stearylamine, is a primary aliphatic amine with the chemical formula C18H37N. It consists of an 18-carbon hydrocarbon chain attached to a terminal amino group, giving it amphiphilic character that underpins many of its uses.

In appearance, octadecylamine is a colorless to white waxy solid at room temperature. It is soluble in many organic solvents such as ethanol, ether, and toluene, but only sparingly soluble in water. As a basic amine, it readily forms ammonium salts with acids and can be protonated under acidic conditions. Its long hydrophobic tail contributes to its surfactant properties, while the amine group provides a reactive site for further derivatization.

Industrial production of octadecylamine typically involves hydrogenation of long-chain nitriles (such as octadecyl nitrile) or related reductive amination routes to install the primary amino group on the C18 chain. Alternative routes include amination of fatty derivatives or lenient transformations of natural waxes and stearic-derived intermediates. The choice of route depends on availability of feedstocks and the desired purity.

Common applications reflect its surfactant and chemical-intermediate character. It is used as a raw material for cationic surfactants and phase-transfer catalysts, as well as in lubricants, corrosion inhibitors, and polymerization aids. It serves as a building block for amide and imide derivatives and for the preparation of quaternary ammonium compounds.

Safety considerations include irritation to skin, eyes, and the respiratory tract. It is a flammable, potentially hazardous substance and should be handled with appropriate protective equipment, in well-ventilated areas, away from oxidizers.