Amines are ammonia molecules (NH3) in which one, two or three hydrogen atoms are replaced by aliphatic and/or aromatic radical. Volatile amines, such as methylamine and ethylamine, smell like ammonia.
Amines of small molecular weight, in which radicals do not exhibit any strong properties, are soluble in water as well as ammonia, due to the association by hydrogen bonding. Aromatic amines are mostly toxic.
Amines are divided into primary, secondary and tertiary, according to the number of substituted hydrogen atoms.
The most interesting amine in the industry is aniline. Aniline is an amine produced in large quantities and greatly influenced the history of organic chemistry. Porous plastics and rubbers, such as polyurethane, are made from aniline.
