"Phenyl ether" redirects here. For the class of compounds, see phenol ether.
Diphenyl ether is the organic compound with the formula (C6H5)2O. It is a colorless, low-melting solid. This, the simplest diaryl ether, has a variety of niche applications.[5]
Involving similar reactions, diphenyl ether is a significant side product in the high-pressure hydrolysis of chlorobenzene in the production of phenol.[7]
The main application of diphenyl ether is as a eutectic mixture with biphenyl, used as a heat transfer fluid. Such a mixture is well-suited for heat transfer applications because of the relatively large temperature range of its liquid state. A eutectic mixture (commercially, Dowtherm A) is 73.5% diphenyl ether and 26.5% biphenyl.[9][10]
Because of its odor reminiscent of scented geranium, as well as its stability and low price, diphenyl ether is used widely in soap perfumes. Diphenyl ether is also used as a processing aid in the production of polyesters.[5]
Several polybrominated diphenyl ethers (PBDEs) are useful flame retardants. Of penta-, octa-, and decaBDE, the three most common PBDEs, only decaBDE is still in widespread use since its ban in the European Union in 2003.[13] DecaBDE, also known as decabromodiphenyl oxide,[14] is a high-volume industrial chemical with over 450,000 kilograms produced annually in the United States. Decabromodiphenyl oxide is sold under the trade name Saytex 102 as a flame retardant in the manufacture of paints and reinforced plastics.
^Byers, Charles H.; Williams, David F. (July 1987). "Viscosities of pure polyaromatic hydrocarbons". Journal of Chemical & Engineering Data. 32 (3): 344–348. doi:10.1021/je00049a018. ISSN0021-9568.