Fluorocarbon refrigerants

In contrast to past environmental problems associated with fluorocarbon refrigerants, the exceptional properties of fluorine in polymers have great environmental value. Some fluoropolymers are enabling green technologies such as hydrogen fuel cells for automobiles and oxygen-selective membranes for cleaner diesel combustion. 

Uses Manufacture of fluorocarbon refrigerants, fluorocarbon plastics, and propellants solvent for natural products analytical chemistry cleansing agent soil fumigant insecticides preparation of chlorodifluoromethane, methyl fluoride, salicylaldehyde cleaning electronic circuit boards in fire extinguishers. 

Downing, Ralph C. Fluorocarbon Refrigerants Handbook. Upper Saddle River, NJ Prentice Hall, 1988. 

Although the technological basis of all fluorine-containing plastics and most elastomers continues to be the free radical polymerization of fluoroolefins, which themselves are based on the vastly greater fluorocarbon refrigerant industry, important advances have been made in the past two decades These include primarily the production of polymers that are more resistant to degradation by heat, oxidation, bases, and solvents, as well as polymers that are more easily processable, that is, able to be converted mto their final forms for use, whether by thermoplastic or thermoset processes [1,2,3,4]... 

Commercially, ahoul MI fr of chloroform is used in production of fluorocarbon refrigerants and propellams. Cl is replaced by ireulmenl with lluonnaicd antimony pentaeliloride. The producl. CHCIF (R-22). is used for home air-conditioning units. It is also used as a feed for production or tetrafluoroethylene. which polymerizes to Teflon. Total demand for chloroform approximates 600 million pounds (136 million kilograms) per year. 

The best-known gas hydrates are those of ethane, ethylene, propane, and isobulaue. Others include methane and I butene, most of the fluorocarbon refrigerant gases, nitrous oxide, acetylene, vinyl chloride, carbon dioxide, methyl and ethyl chloride, methyl and ethyl bromide, cyclopropane, hydrogen sulfide, methyl mercaptan, and sulfur dioxide. 

General Motors and then became vice president of Ethyl Corporation, as well as of the Ohio State University Research Foundation. His innovative genius was responsible for the development of organic lead compounds for antiknock gasoline and later for the discovery of fluorocarbon refrigerants for which he did the basic research. He was recipient of many of chemistry s highest honors including the Nichols medal, the Perkin medal, and the Priestly medal. 

Midgley, Thomas (1889-1944). Discovered tetraethyllead and antiknock treatment for gasoline (1921) and fluorocarbon refrigerants early research on synthetic rubber. 

Freon. PuPont] Fluorocarbons refrigerants, solvents, blowing agents, dielectric gases, plastics, interm ates, aerosol propellants. 

T. Fujii, H. Honda, and S. Nozu, Condensation of Fluorocarbon Refrigerants Inside a Horizontal Tube—Proposals of Semi-Empirical Expressions for the Local Heat Transfer Coefficient and the Interfacial Friction Factor, Refrigeration, 55(627), pp. 3-19,1980 (in Japanese). 

PA-6 or PA-66 and >50% acrylic elastomers has been introduced by DuPont (Zytel FN) as a plasticizer-free, low modulus composition with good low-temperature toughness, resistance to thermal aging and solvents (particularly to fluorocarbon refrigerants) (Table 15.17). 

R. C. Downing, Fluorocarbon Refrigerants Handbook, Prentice-Hall, Englewood Cliffs, NJ, 1988. 

Refrigerants. Fluorocarbon refrigerants are standard matmals in chlor-alkali applications. They are inert and not toxic. Principal hazards are the low temperatures encountered and the asphyxiating property of the gases. Those using other refngerants (ammonia and hydrocarbons are examples) must provide for their particular hazards in design and operation. 

The major concern with fluorocarbon refrigerants is not personnel hazards but then-ozone depletion potential. Many types that were popular in the past are now banned by the Montreal Protocol or successor agreements (Section 9.1.7.2B). Handling and disposal of refrigerants with the potential for depleting the stratospheric ozone layer... 

Late In the 19th Century the Belgiam chemist Swartz established the chemistry for the introduction of fluorine into organic compounds which first achieved commercial status in the fluorocarbon refrigerant Industry. 

The following reaction, depicted using molecular models, is used to make carbon tetrachloride, CCI4, a solvent and starting material for the manufacture of fluorocarbon refrigerants and aerosol propellants. 

Flash point see Flammability Flattening factor for the earth, 14-1 Fluorescent Indicators, 8-18 to 19 Fluorine see also Elements critical constants, 6-39 to 58 electron configuration, 1-18 to 19 heat capacity, 4-135 history, occurrence, uses, 4-1 to 42 ionization energy, 10-203 to 205 isotopes and their properties, 11-56 to 253 physical properties, 4-133 to 134 thermodynamic properties, 5-1 to 3 thermodynamic properties at high temperature, 5-43 to 65 vapor pressure, 6-61 to 90,6-91 to 98 Fluorocarbon refrigerants, 6-133 to 135 Foods... 

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