Adipic acid
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| Adipic acid | |
|---|---|
 |
|
| General | |
| Common name | adipic acid |
| Systematic name | butane-1,4-dicarboxylic acid |
| Other names | hexanedioic acid |
| Molecular formula | C6H10O4 |
| SMILES | OC(=O)CCCCC(=O)O |
| Molar mass | 146.14 g/mol |
| Appearance | White crystals |
| CAS number | [124-04-9] |
| Properties | |
| Density and phase | 1.36 g/cm³ |
| Solubility in water | slightly soluble |
| Other solvents ethanol, acetone |
soluble |
| Melting point | 152 °C (425 K) |
| Boiling point | 337 °C (610 K) |
| Acidity | pKa1=4.42 pKa2=5.42 |
| Structure | |
| Molecular shape | ? |
| Coordination geometry | ? |
| Crystal structure | ? |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | flammable |
| Flash point | 232 °C |
| R/S statement | R: 36 S: n/a |
| RTECS number | ? |
| Supplementary data page | |
| Structure & properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| 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 |
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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.
[edit] Preparation
Historically, adipic acid is prepared from various fats using oxidation. Current commercial adipic acid is produced from cyclohexane by two oxidation steps.
- Cyclohexane + O2 → cyclohexanol and cyclohexanone
- cyclohexanol/cyclohexanone + nitric acid + air → adipic acid + nitrous oxide
Utilizing Principles of Green chemistry, a new method of synthesis involves:
Cyclohexene + hydrogen peroxide with a phase transfer catalyst to produce adipic acid.
(Reported in Science, "A green route to adipic acid: direct oxidation of cyclohexenes with 30 percent hydrogen peroxide")
The waste product is just water.
[edit] 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, the most common form of 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)
