Diphenylamine is mainly used as antioxidant of synthetic rubber, fuel and pharmaceutical intermediate, antioxidant of lubricating oil and stabilizer of gunpowder.

Verification of nitrate, chlorate and other oxidizing substances. Catalytic determination of iridium. Spectrophotometric Determination of nitrate. Redox indicator. Haploid breeding medium. Making dyes. It is a stabilizer for nitrocellulose, explosives and firewool.

Properties of diphenylamine: diphenylamine is a non-polar aromatic organic molecule, with a melting point lower than that of water, slightly soluble in water, and easily soluble in alcohol, glacial acetic acid and other organic solvents. It is chemically active and easy to change color when exposed to light. Therefore, it should be stored in the dark. Diphenylamine is toxic

Diphenylamine solution will appear white turbidity (diphenylamine will precipitate in large amount after contacting water), and the white turbidity may disappear after water bath heating When more diphenylamine reagent is added, the acetic acid concentration in the whole mixed solution system will increase correspondingly. Since diphenylamine can be well dissolved in acetic acid, it is not surprising that the white turbidity disappears