O-phenylphenol (OPP), also known as 2-hydroxybiphenyl or 2-phenylphenol, is a white or light yellow or light red powder, flake or cake with a weak phenolic taste.
Melting point 55.5~57.5°C,
Boiling point 283 ~ 286 ° C (0.1 MPa),
The relative density is 1.213 (20 ° C),
The flash point is 123.9 °C. Slightly soluble in water,
Soluble in organic solvents such as methanol, acetone, benzene, xylene, trichloroethylene, dichlorobenzene.
Sodium o-phenylphenolate is abbreviated as SOPP, which is a white flake or a cake or a pale red powder, and is highly soluble in water.
There are three production methods for o-phenylphenol, and the specific introduction is as follows:
It can be recovered from the distillation residue of phenol produced by sulfonation.
The distillation residue of phenol contains about 40% of phenylphenol, and other components are phenol, inorganic salts, water, and the like. After vacuum distillation, the fraction of mixed phenylphenol fraction is separated, the degree of vacuum is 53.3-66.7 kPa, and the temperature starts to intercept above 100 °C at 65-75 °C, but not more than 1345 °C. Reusing the solubility of o- and p-hydroxybiphenyl in trichloroethylene, the two are separated into pure substances. The mixed materials (mainly 2-hydroxybiphenyl and 4-hydroxybiphenyl) are heated and dissolved in trichloroethylene, and after cooling, 4-hydroxybiphenyl crystals are precipitated, which are centrifuged and dried to obtain 4-hydroxybiphenyl. . The mother liquor is washed with a sodium carbonate solution, and a dilute alkali solution is added to form a 2-hydroxybiphenyl salt. After standing and stratification, the upper layer of 2-hydroxybiphenyl sodium salt is dehydrated under reduced pressure to obtain a finished sodium salt. The sodium 2-hydroxybiphenyl salt is a white to light red powder. Very soluble in water, soluble in 122g water 122g, 2% aqueous solution pH 11.1-12.2. Also soluble in acetone, methanol, soluble in glycerin, but insoluble in oil. The 2-hydroxybiphenyl sodium salt is acidified to produce 2-hydroxybiphenyl, both of which are food additives.
It is obtained by heating dibenzofuran and sodium metal to about 200 ° C and decomposing the product with an acid.
It is obtained by hydrolysis of 2-aminobiphenyl by diazotization.