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建立人际资源圈CFCs_And_Alternative_Aerosol_Propellents
2013-11-13 来源: 类别: 更多范文
CFCs And Alternative Aerosol Propellents
In todays modern world of throw-away packaging, Styrofoam, and plastics, many manufacturers produce products, whether intentional or not, that are harmful to the environment. Chlorofluorocarbon is just one of those products. Created in the late 20s and believed to be harmless to the environment, chlorofluorocarbon was used in just about anything that needed a propellant or anything that needed a refrigerant. After being banned in the United States in the 80s, many manufactures had to turn to alternative propellant sources.
In 1928, an industrial organic scientist by the name of Thomas Midgley was working at a research lab at General Motors. There he discovered two inert, nontoxic, nonflammable gasses with excellent refrigerant properties (Fisher). These two gasses were dichlorodifluoromethane and trichloromonofluoromethane, which are both simple variations of methane. Methane has the formula CH4, where there are four hydrogen molecules for each carbon molecule. In dichlorodifluoromethane, chlorine and fluorine replace the hydrogen to have the formula CCl2F2. In trichloromonofluoromethane, the four hydrogen are kicked out and replaced with three chlorines and only one fluorine. Combined together they create chlorofluorocarbon, or CFC. By 1938, 15% of the refrigerant market was held by CFCs, which were marketed by du Pont under the name Freon.
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