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 (346KB)
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38,317,000 Yen (FY1998; 12,349,000 Yen)
The strategy for the development of bromine-free halon replacement with high fire extinguishing ability is the use of as much as CF3 radicals generated from fluorocompounds in fire, of which CF3 radicals act the role of fire suppression played by the bromine atom. Thus, as the target bromine-free halon replacement, fluorine-containing compounds having the molecular structure in which CF3- and C2F5- groups bonded directly to the hetero-atom (oxygen, nitrogen and sulfur) were synthesized and their fire extinguishing ability was evaluated by the measurement of laminar flame velocities of methane and heptane flames, and by the extinction test by a cup burner. It was found that among these compounds, polyfluoroamines showed the best fire extinguishing ability compared with polyfluorocompounds and those of O and S containing compounds. However, the latter two compounds showed comparable fire extinguishing ability to that of FM200 and FE23 which were put in practical use. For the explanation of good fire suppression of perfluoroamines represented by (CF3)2NC2F5, the computational chemistry study was conducted on the reaction of C2F5 radical with hydroxyl and hydrogen radical comparing with that of CF3-radical. As far as the action between perfluoroalkyl radical and hydrogen and hydroxyl radicals in flame is concerned, it was found that C2F5-radical behaves more effectively than CF3 radical as hydroxyl and hydrogen radical scavenger.
Halon alternatives. Fire extinguisher, perfluoroamine, laminar flame speed, Pentafluoroethyl radical, Fire supression mechanism, Polyfluoroamines, polyfluoroethers, Polyfluorosulfur compound.