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Phosgene is an organic chemical compound with the formula COCl 2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut ...
Polycarbonate is commonly used in eye protection, as well as in other projectile-resistant viewing and lighting applications that would normally indicate the use of glass, but require much higher impact-resistance. Polycarbonate lenses also protect the eye from UV light.
Polycarbonate derived from bisphenol A is produced in this manner. This process is high yielding. However, toxic phosgene is used, and stoichiometric quantities of base (e.g. pyridine) are required to neutralize the hydrogen chloride that is cogenerated. [2] [3] Chloroformate esters are intermediates in this process.
About 65–70% of all bisphenol A is used to make polycarbonate plastics, [9] [10] which can consist of nearly 90% BPA by mass. Polymerisation is achieved by a reaction with phosgene, conducted under biphasic conditions; the hydrochloric acid is scavenged with aqueous base. [43]
The use of phosgene can be avoided by the oxidative carbonylation of phenol with carbon monoxide: [2] 2 PhOH + CO + [O] → PhOCO 2 Ph + H 2 O. Dimethyl carbonate can also be transesterified with phenol: CH 3 OCO 2 CH 3 + 2 PhOH → PhOCO 2 Ph + 2 MeOH. The kinetics and thermodynamics of this reaction are not favorable.
Traces of a toxic, colorless gas were found at the headquarters of Sweden’s security agency where a suspected gas leak last week forced authorities to evacuate some 500 people from the facility ...
Oxidation of tetrachloroethylene by ultraviolet radiation in air produces trichloroacetyl chloride and phosgene: 4 C 2 Cl 4 + 3 O 2 → 2 CCl 3 COCl + 4 COCl 2. This reaction can be halted by using amines and phenols (usually N-methylpyrrole and N-methylmorpholine) as stabilisers. But the reaction can be done intentionally to produce ...
Some residents he wasn’t sure about, and he ordered them to exhale into a plastic breathalyzer. Merrick didn’t think the device was working. With each attempt, there was only a flicker on the digital readout, maybe just part of a 5, maybe half of a 0.