Cyclohexanone: Chemical and physical properties, Production and Uses

Cyclohexanone is a six-carbon ring molecule with a ketone functional group. It is a colourless to pale yellow oily liquid with an acetone-like odour. It is mainly used as an intermediate in the production of nylon.

Chemical and physical properties of Cyclohexanone

• Formula: C6H10O

• Molar mass: 98.15 g/mol

• Appeareaces: Colourless to light yellow oily liquid

• Odour: Peppermint and acetone odour
  

• Density: 948 kg/m³
  

• Boiling-point: 155.6°C
  

• Melting-point: −47 °C
  

• Flash-point: 111°F
  

• Solubility: Miscible with most organic solvents. Soluble in ethanol, diethyl ether, benzene, chloroform and other common organic solvents; soluble in water (150 g/1 at 10°C, 50 g/1 at 30°C)
  

• Vapour pressure: 5.2 mm Hg at 25°C
  

• Refractive index: 1.4507 at 20°C

Production of Cyclohexanone

Cyclohexanone is produced commercially in several major ways. One widely used process yields cyclohexanol and cyclohexanone by the catalytic oxidation of cyclohexane. The cyclohexanol/cyclohexanone product mixture, also called KA oil, is further reacted to produce adipic acid and hexamethylene diamine, intermediates in the manufacture of nylon 66. Pure cyclohexanone can be produced in high yields by this process either by distillation or by catalytic dehydrogenation of the cyclohexanol.

Another important and very efficient process is based on the hydrogenation of phenol. The cyclohexanone produced is further reacted to produce cyclohexanone oxime, an intermediate which then can undergo a Beckmann rearrangement to yield caprolactam, the important intermediate for nylon 6.

Uses of Cyclohexanone

Cyclohexanone is used predominantly for the synthesis of raw materials used in the production of nylon. The remainder is used as a chemical intermediate in other processes, as an additive or as a high-boiling, slow-drying solvent. Cyclohexanone is used as a solvent in insecticides, wood stains, paint and varnish removers, spot removers, cellulosics, and natural and synthetic resins and lacquers. Additive uses include detergents, degreasing of metals, mould release agent for paints or varnishes, levelling agent in dyeing and delustering silk, and lube oil additive, especially for aircraft piston-type engines. Cyclohexanone is also used as a monomer in the synthesis of cyclohexanone resins, polyvinyl chloride and its copolymers, and methacrylate ester polymers.

References:

[1] QIUYUE ZHOU. Engineering Pt-Bi2O3 Interface to Boost Cyclohexanone Selectivity in Oxidative Dehydrogenation of KA-Oil[J]. Catalysts, 2021. DOI:10.3390/catal11101187.