Английская Википедия:Diphenyl carbonate

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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[1][2] and a product of the decomposition of polycarbonates.[3]

Production

World production capacity of diphenyl carbonate was 254,000 tonnes in 2002, and phosgenation of phenol is the most significant route.[4] 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:[1]

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.[1] 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.[5]

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.[1]

References

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