Caprolactam degradation
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| Names | |||
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IUPAC name
Azepan-2-one
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Systematic IUPAC name
Hexano-6-lactam
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| Other names
ε-Caprolactam
1-Aza-2-cycloheptanone 2-Azacycloheptanone Capron PK4 Cyclohexanone iso-oxime Extrom 6N Hexahydro-2-azepinone Hexahydro-2H-azepin-2-one (9CI) Hexanolactam Aminocaproic lactam |
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| Identifiers | |||
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3D model (JSmol)
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.003.013 | ||
| EC Number | 203-313-2 | ||
| KEGG | |||
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PubChem CID
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| UNII | |||
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| Properties | |||
| C6H11NO | |||
| Molar mass | 113.16 g·mol−1 | ||
| Appearance | White solid | ||
| Density | 1.01 g/cm3 | ||
| Melting point | 69.2 °C (156.6 °F; 342.3 K) | ||
| Boiling point | 270.8 °C (519.4 °F; 544.0 K) at 1013.25 hPa | ||
| 866.89 g/L (22 °C) | |||
| Vapor pressure | 0.00000008 mmHg (20° C) | ||
| Hazards | |||
| R-phrases (outdated) | R20, R22, R36/37/38 | ||
| Flash point | 125 °C (257 °F; 398 K) | ||
| Explosive limits | 1.4%-8.0% | ||
| US health exposure limits (NIOSH): | |||
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PEL (Permissible)
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none | ||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |||
Caprolactam (CPL) is an organic compound with the formula (CH2)5C(O)NH. This colourless solid is a lactam (a cyclic amide) of caproic acid. Global demand for this compound is approximately 5 million tons per year, and the vast majority is used to make Nylon 6 filament, fiber, and plastics..
Caprolactam was first described in the late 1800s when it was prepared by the cyclization of ε-aminocaproic acid, the product of the hydrolysis of caprolactam. World demand for caprolactam was estimated to reach 5 million tons per year for 2015. 90 % of caprolactam produced is used to make filament and fiber, 10 % for plastics, and a small amount is used as a chemical intermediate. Due to its commercial significance, many methods have been developed for the production of caprolactam. It was estimated that 90 % of all caprolactam is synthesised from cyclohexanone (1), which is first converted to its oxime (2). Treatment of this oxime with acid induces the Beckmann rearrangement to give caprolactam (3):
The immediate product of the acid-induced rearrangement is the bisulfate salt of caprolactam. This salt is neutralized with ammonia to release the free lactam and cogenerate ammonium sulfate. In optimizing the industrial practices, much attention is directed toward minimizing the production of ammonium salts.
The other major industrial route involves formation of the oxime from cyclohexane using nitrosyl chloride, and this method accounts for 10 % of world production. The advantage of this method is that cyclohexane is less expensive than cyclohexanone.
Other paths to caprolactam include the depolymerization of waste Nylon 6, and the reaction of caprolactone with ammonia. At bench scale, the reaction between cyclohexanone with hydrazoic acid to give caprolactam in the Schmidt reaction has been reported.
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Wikipedia