adipic acid

Adipic acid
IUPAC name	hexanedioic acid
Other names	butane-1,4-dicarboxylic acid
Identifiers
CAS number	124-04-9
SMILES	OC(=O)CCCCC(=O)O
Properties
Molecular formula	C6H10O4
Molar mass	146.14 g/mol
Appearance	White crystals
Density	1.36 g/cm³
Melting point	152 °C (425 K)
Boiling point	337 °C (610 K)
Solubility in water	slightly soluble
Hazards
Main hazards	flammable
R-phrases	R: R36
Flash point	232 °C
Related Compounds
Related dicarboxylic acids	glutaric acid pimelic acid
Related compounds	hexanoic acid
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Adipic acid (IUPAC systematic name: hexanedioic acid) is a chemical compound of the class of carboxylic acids. It is a white crystalline powder appearing as an acid in aqueous circumstances, though it is not highly soluble.

Preparation

Historically, adipic acid is prepared from various fats using oxidation. Current commercial adipic acid is produced from cyclohexane by two oxidation steps.

1. Cyclohexane + O₂ → cyclohexanol and cyclohexanone
2. cyclohexanol/cyclohexanone + nitric acid + air → adipic acid + nitrous oxide

(The mixture of cyclohexanol and cyclohexanone produced from cyclohexane is commercially called "KA oil", the abbreviation of "Ketone-Alcohol oil".)

Utilizing Principles of Green chemistry, a new method of synthesis involves:

Cyclohexene + hydrogen peroxide with a tungsten catalyst under phase transfer conditions to produce adipic acid.^[1] The waste product is water.

Uses

By far the main use of adipic acid is as monomer for the production of nylon by a polycondensation reaction with hexamethylene diamine forming 6,6-nylon. Other uses include:

• Monomer for production of Polyurethane

• reactant to form plasticizers and lubricant components

• Food Ingredient as a flavorant and gelling aid.E-number E355.

• FDA citations - GRAS (21 CFR 184.1009), Indirect additive (21 CFR 175.300, 21 CFR 175.320, 21 CFR 176.170, 21 CFR 176.180, 21 CFR 177.1200, 21 CFR 177.1390 , 21 CFR 177.1500, 21 CFR 177.1630 , 21 CFR 177.1680, 21 CFR 177.2420, 21 CFR 177.2600)

References

1. ^ Sato K, Aoki M, Noyori R (1998). "A "Green" route to adipic acid: direct oxidation of cyclohexenes with 30 percent hydrogen peroxide". Science 281 (5383): 1646-7. PMID 9733504. 

External links

• adipic acid on chemicalland
• SOlutia Inc product website

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