Diphenylamine
[CAS# 122-39-4]

Identification

• Classification: Organic raw materials >> Amino compound >> Cycloalkylamines, aromatic monoamines, aromatic polyamines and derivatives and salts
• Name: Diphenylamine
• Synonyms: Diphenylamine redox
• Molecular Formula: C₁₂H₁₁N
• Molecular Weight: 169.22
• CAS Registry Number: 122-39-4
• EC Number: 204-539-4
• SMILES: C1=CC=C(C=C1)NC2=CC=CC=C2

Properties

• Density: 1.16 g/mL
• Melting point: 52-54 ºC
• Boiling point: 302 ºC
• Flash point: 152 ºC
• Water solubility: Slightly soluble. 0.03 g/100 mL

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08;GHS09 Danger
• Hazard Statements: H301-H311-H319-H331-H373-H400-H410
• Precautionary Statements: P260-P261-P262-P264-P264+P265-P270-P271-P273-P280-P301+P316-P302+P352-P304+P340-P305+P351+P338-P316-P319-P321-P330-P337+P317-P361+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	3	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	3	H331
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Eye irritation	Eye Irrit.	2	H319
Carcinogenicity	Carc.	2	H351
Serious eye damage	Eye Dam.	1	H318
Skin irritation	Skin Irrit.	2	H315
Flammable solids	Flam. Sol.	2	H228
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	1	H370
Reproductive toxicity	Repr.	2	H361

• Transport Information: UN 2811;UN 3077

Discovory and Applicatios

Diphenylamine, chemically known as diphenylaminomethane, is an organic compound with the molecular formula C12H11N. It is a member of the amine family, characterized by the presence of two phenyl groups attached to a nitrogen atom. The compound was first synthesized in the 19th century, with its discovery attributed to various researchers who explored the chemistry of anilines and their derivatives. Diphenylamine has gained significant attention due to its versatile applications across multiple industries.

The synthesis of diphenylamine typically involves the reaction of aniline with benzene in the presence of an acid catalyst, often utilizing Friedel-Crafts alkylation or amination processes. This reaction results in the formation of diphenylamine along with the release of hydrogen. The compound exhibits a distinctive pale yellow to white crystalline appearance and possesses a characteristic aromatic odor.

Diphenylamine is widely used in the rubber industry as an antioxidant. Its ability to prevent the oxidative degradation of rubber products helps to extend their lifespan and maintain their performance. The compound works by scavenging free radicals generated during the oxidation process, thereby protecting the rubber matrix from deterioration. As a result, diphenylamine is commonly found in tires, seals, and various rubber goods, contributing to their durability and resistance to aging.

In addition to its role in rubber manufacturing, diphenylamine is employed as a corrosion inhibitor in metalworking fluids. Its ability to form a protective layer on metal surfaces helps to prevent rust and corrosion, making it valuable in the maintenance of machinery and equipment. This application is particularly important in industries such as automotive and aerospace, where metal components are subject to harsh environmental conditions.

Diphenylamine also finds use in the production of dyes and pigments. Its chemical structure allows for modifications that lead to the synthesis of various colored compounds, which are then used in textiles, plastics, and coatings. The versatility of diphenylamine derivatives contributes to the development of a wide range of hues and shades, enhancing the aesthetic appeal of consumer products.

Moreover, diphenylamine has been utilized in analytical chemistry as a reagent for detecting specific ions. It is often used in the field of food safety, where it serves as an indicator for the presence of nitrite in food products. The reaction of diphenylamine with nitrites results in a color change, providing a visual cue for the presence of these potentially harmful compounds.

Despite its numerous applications, diphenylamine is not without concerns regarding its safety and environmental impact. It is classified as a hazardous substance, with potential health effects that may arise from prolonged exposure, including respiratory issues and skin irritation. Regulatory agencies, such as the U.S. Environmental Protection Agency (EPA), have established guidelines to ensure the safe handling and use of diphenylamine in industrial processes.

In recent years, there has been a growing emphasis on the development of safer alternatives to diphenylamine, particularly in light of environmental and health considerations. Research efforts are focused on exploring more sustainable practices and finding substitutes that can deliver similar performance without the associated risks.

In summary, diphenylamine is a significant compound with diverse applications in the rubber, metalworking, and dye industries. Its discovery and continued use highlight the importance of amines in various chemical processes. As research advances, the focus on safety and sustainability will shape the future of diphenylamine and its derivatives in industrial applications.

References

1979. Influences of inducers and inhibitors of the microsomal monooxygenase system on the alkylating intensity of dimethylnitrosamine in mice. Journal of Cancer Research and Clinical Oncology.
DOI: 10.1007/bf00405349

1984. Environmental transformations of DPA, SOPP, benomyl, and TBZ. Residue reviews.
DOI: 10.1007/978-1-4612-5266-5_4

2024. Preparation and characterization of hydroxyl-terminated polybutadiene graft ferrocene based composite. Journal of Polymer Research.
DOI: 10.1007/s10965-024-04204-z