Phosgene physical properties

Physical Properties Phosgene is a colorless gas at room temperature with a density, relative to air, of 3.4. It has mp of — 118°C, bp of 8°C, and vapor pressure of approximately 1200 mm at 20°C. It is slightly soluble in water, in which it hydrolyzes, and rather soluble in most hydrocarbons (e.g., hexane and benzene) and in glacial acetic acid. Phosgene has an odor of newly mown or musty hay. It is estimated that the least detectable odor occurs at approximately 1 ppm, but that the lowest concentration affecting the eyes is about 4 ppm. 

TABLE 1. Physical Properties of Polycarbonate Prepared Using Bisphenol A, 3,3-bis(4-hydroxy-phenyl)-l-phenyl-lH-indol-2-one, and Phosgene Dissolved in C Cb/Chlorobenzene at Ambient Temperature... 

Volume 1 Includes Introduction, some considerations on physical properties and chemical reactivity, and four chapters devoted to phosgene and derivatives as building blocks. 

Some physical properties of phosgene are presented in table 2-1. 

Only a few of the physical properties of COBrF have been measured. Carbonyl bromide fluoride (relative molecular mass 126.91) is a colourless gas, with an odour similar to, but distinguishable from, phosgene [1195]. The melting point at atmospheric pressure of COBrF has been reported as -120 2 C [1196a], and the boiling point as -20.6 "C [1196a]. Its critical temperature occurs at +124 C, and its critical pressure is ca. 6.18 MPa [656a,1751]. 

Phosgene is, at ordinary temperatures and pressures, a colourless gas with a suffocating smell said to be reminiscent of mouldy or sometimes freshly-mown hay. Its chemical and physical properties are shown in Table 1. 

Other types of polycarbonates have also been made using a very different approach from that involving bisphenol A and related compounds. For example, the reaction between phosgene and allyl alcohol (CH2=CHCH2OH) produces a monomer with carbon-carbon double bonds at both ends of the molecule that can be used for polymerization. Interestingly enough, the polycarbonate produced by this process has very different physical properties from the traditional bisphenol A polymer. The allyl polymer is a clear, transparent, flexible plastic whose primary use is in the production of eyeglass lenses. 

From this background synthesis of copolymers of the various chlorinated blsphenols with blsphenol A was carried out at both high and low levels of Incorporation In order to obtain a clearer overall assessment of their physical properties. In all cases random copolymerization with blsphenol A was attempted via solution polymerization with phosgene In the presence of pyridine catalyst. 

Tab. 3.2. Physical properties of phosgene and phosgene equivalents and substitutes [15],...

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