Propellants difluoroethane

The catalytic hydrofluorination of acetylene has been reported in detail.24,5 34-541 The reaction products are polymerizable fluoroethene (1) and 1,1-difluoroethane, which can be used as a coolant or low boiling solvent, e.g. as an aerosol propellant. 

Chlorodifluoroethane is a hydrochlorofluorocarbon (HCFC) aerosol propellant previously used in topical pharmaceutical formulations. However, it is no longer permitted for use in pharmaceutical formulations because its harmful effects on the environment. It was also generally used in conjunction with difluoroethane to form a propellant blend with a specific gravity of 1. Chlorodifluoroethane was also used in combination with chlorodifluoromethane and hydrocarbon propellants. Chlorodifluoroethane may be used as a vehicle for dispersions and emulsions. 

Difluoroethane is a nonreactive and stable material. The liquefied gas is stable when used as a propellant and should be stored in a metal cylinder in a cool, dry place. 

Difluoroethane, a hydrofluorocarbon (HFC), is an aerosol propellant used in topical pharmaceutical formulations. Difluoroethane may be used as a vehicle for dispersions and emulsions. 

Under the terms of the Montreal Protocol, aimed at reducing damage to the ozone layer, the use of chlorofluorocarbons has been prohibited since January 1996. Since difluoroethane does not contain chlorine, there are no environmental controls on the use of this material as a propellant, since it does not deplete the ozone layer and is not a greenhouse gas. 

Difluoroethane may be used as an aerosol propellant in topical pharmaceutical formulations. It is generally regarded as an essentially nontoxic and nonirritant material. 

Difluoroethane is usually encountered as a liquefied gas and appropriate precautions for handling such materials should be taken. Eye protection, gloves, and protective clothing are recommended. Difluoroethane should be handled in a well-ventilated environment. Fluorocarbon vapors are heavier than air and do not support life therefore, when cleaning large tanks that have contained these propellants, adequate provision for oxygen supply in the tanks must be made in order to protect workers cleaning the tanks. 

Difluoroethane is useful as an aerosol propellant in that it shows greater miscibility with water than some other fluorocarbons and when combined with chlorodifluoroethane will produce a mixture with a specific gravity of 1. For a discussion of the numerical nomenclature applied to this aerosol propellant, see Ghlorofluorocarbons. 

Propei . See Lactic acid Propellant 11. See Trichlorofluoromethane Propellant 12. See Dichlorodifluoromethane Propellant 22. See Chlorodifluoromethane Propellant 23. See Trifluoromethane Propellant 114. See 1,2-Dichlorotetrafluoroethane Propellant 142b. See 1,1,1-Chlorodifluoroethane Propellant 152a. See 1,1-Difluoroethane Propellant C-318. See Octafluorocyclobutane Prop-2-enal 2-Propenal. See Acrolein... 

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