Diphenyl carbonate is the organic compound with the formula (C6H5O)2CO. It is classified as an acyclic carbonate ester. It is a colorless solid. It is both a monomer in combination with bisphenol A in the production of polycarbonate polymers[2][3] and a product of the decomposition of polycarbonates.[4]
Production
World production capacity of diphenyl carbonate was 254,000 tonnes in 2002, and phosgenation of phenol is the most significant route.[5] Phosgenation of phenol can proceed under various conditions. The net reaction is as follows:
- 2 PhOH + COCl2 → PhOCO2Ph + 2 HCl
The use of phosgene can be avoided by the oxidative carbonylation of phenol with carbon monoxide:[2]
- 2 PhOH + CO + [O] → PhOCO2Ph + H2O
Dimethyl carbonate can also be transesterified with phenol:
- CH3OCO2CH3 + 2 PhOH → PhOCO2Ph + 2 MeOH
The kinetics and thermodynamics of this reaction are not favorable. For example, at higher temperatures, dimethyl carbonate undesirably methylates phenol to give anisole.[2] Despite this, diphenyl carbonate made from non-phosgene sources has become a widely used raw material for the synthesis of bisphenol-A-polycarbonate in a melt polycondensation process.[6]
Applications
Polycarbonates can be prepared by transesterifying diphenyl carbonate with bisphenol A. Phenol is a co-product. These polycarbonates may be recycled by reversing the process: transesterifying the polycarbonate with phenol to yield diphenyl carbonate and bisphenol A.[2]
References
- ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 3–238, ISBN 0-8493-0594-2
- ^ a b c d Hans-Josef Buysch (2000). "Carbonic Esters". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_197. ISBN 978-3-527-30673-2.
- ^ Wittcoff, Harold; Reuben, B. G.; Plotkin, Jeffrey S. (2004), Industrial Organic Chemicals, Wiley-IEEE, p. 278, ISBN 978-0-471-44385-8, retrieved 2009-07-20
- ^ ASM International (2003), Characterization and Failure Analysis of Plastics, ASM International, p. 369, ISBN 978-0-87170-789-5, retrieved 2009-07-20
- ^ "Diphenyl Carbonate" (PDF). IPSC Inchem. Archived from the original (PDF) on 2012-01-04. Retrieved 2012-08-01.
- ^ Fukuoka, Shinsuke (2012). Non-Phosgene Polycarbonate from CO2 - Industrialization of Green Chemical Process. Nova Science Publishers. ISBN 9781614708773.