Figure shows the supply chain of aromatic diamine which, unsurprisingly, utilities aromatic building blocks such as benzene and phenol. The nitrogen introduction occurs via oxidation reaction with nitric acid, followed by reduction reactions to obtain an aromatic amine (i.e., aniline). By comparison Figure shows, aliphatic amines typically result from ammonia exchange with halides. While both nitric acid and ammonia are high-volume, low-cost chemical feedstocks, ammonia is a typically a precursor to nitric acid. Using ammonia directly as the nitrogen source permits a more straightforward supply chain for aliphatic amines than aromatic amines.