1,1,2-trichloro 1,2,2-trifluoroethane

The use of ultra-fine AP to increase the burning rates of double-base propints has been described previously. This technology has also been used with hydrocarbon binders, but dispersion and high viscosity have presented mixing problems. Fine AP can be conveniently dispersed by slurrying first with a surfactant and an organic liq such as 1,1,2-trichloro-1,2,2-trifluoroethane or normal hexane in a process described by Alley (Ref 58a). Sodium sulfonate... 

Moore [355] used the solvent extraction procedure of Danielson et al. [119] to determine iron in frozen seawater. To a 200 ml aliquot of sample was added lml of a solution containing sodium diethyldithiocarbamate (1% w/v) and ammonium pyrrolidine dithiocarbamate (1 % w/v) at pH to 4. The solution was extracted three times with 5 ml volumes of 1,1,2 trichloro-1,2,2 trifluoroethane, and the organic phase evaporated to dryness in a silica vial and treated with 0.1 ml Ultrex hydrogen peroxide (30%) to initiate the decomposition of organic matter present. After an hour or more, 0.5 ml 0.1 M hydrochloric acid was added and the solution irradiated with a 1000 W Hanovia medium pressure mercury vapour discharge tube at a distance of 4 cm for 18 minutes. The iron in the concentrate was then compared with standards in 0.1 M hydrochloric acid using a Perkin-Elmer Model 403 Spectrophotometer fitted with a Perkin-Elmer graphite furnace (HGA 2200). 

To analyze charcoal tubes or vapor monitors for hydrocarbons by IR, the desorption solvent would have to be IR inactive in the region 3100 to 2750 cm-. Two such solvents Freon R 113 (1,1,2 trichloro-1,2,2-trifluoroethane) and perchloroethylene meet this requirement. 

As discussed (vide supra) disproportionation and isomerization are often competitive reactions. The reaction rates of both types depend on the temperature and the catalyst used for the reaction. Chromium(III) oxide on support, or without, favors the disproportionation of 1,1,2-trichloro-1.2,2-trifluoroethane to give l,l-dichloro-l,2.2,2-tetrafluoroethane and 1,1,1.2-tetra-chloro-2,2-difluoroethane whereas with aluminum trifluoridc the isomerization is favored.24 The higher the chlorine content of the molecules the greater is their reactivity. 

FIGURE 5.1.4.7.2 Logarithm of vapor pressure versus reciprocal temperature for 1,1,2-trichloro-1,2,2-trifluoroethane. 

Cabot, P.L., Centelles, M., Segarra, L. andCasado, J. (1997) Palladium-assisted electrodehalogena-tion of 1,1,2-trichloro-1,2,2-trifluoroethane on lead cathodes combined with hydrogen diffusion anodes. J. Electrochem. Soc. 144, 3749-3757. 

The Step 1 product (0.12 mmol) dissolved in 1.2 ml of 1,1,2,-trichloro-1,2,2-trifluoroethane and 20 ml of distilled water were introduced into a 50 ml steel reactor equipped with a magnetic stirrer. The reactor contents were cooled with liquid nitrogen and evacuated to 1 x 10 mbar to remove trace amounts of oxygen. The reactor was next charged with 22 atm of vinylidene fluoride and the reactor temperature, raised to 57°C. Once the autoclave pressure decreased to 15 atm, additional vinylidene fluoride was added to maintain the reaction pressure at 20 atm. The polymerization was stopped after 48 hours, and the product was isolated in 90% yield. 

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