- Preparation method of perfluoroheptanoic acid
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The invention relates to the technical field of fluorochemical preparation, particularly a preparation method of perfluoroheptanoic acid. The method comprises the following steps: oxidizing dodecafluoroheptanol to obtain dodecafluoroheptanoic acid, carrying out reaction on the dodecafluoroheptanoic acid and thionyl chloride to obtain dodecafluoroheptanoyl chloride, carrying out fluorination on the dodecafluoroheptanoyl chloride to obtain perfluoroheptanoyl chloride, and hydrolyzing to obtain the perfluoroheptanoic acid. The technical process of preparing perfluoroheptanoic acid from dodecafluoroheptanol has the advantages of low energy consumption, no pollution and high yield (up to 75% or above), is easy to operate, and has higher competitive edges than the existing perfluoroheptanoic acid production technique.
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Paragraph 0014; 0015; 0016
(2017/07/22)
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- Thermal Decomposition of Some Perfluoro- and Polyfluorodiacyl Peroxides
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Seven polyfluoroacyl peroxides were synthesized, some of them by a new procedure involving the direct interaction of an acyl fluoride with hydrogen peroxide.In the temperature range of 20-40 deg C, all these peroxides undergo first-order decomposition in dilute 1,1,2-trichloro-1,2,2-trifluoroethane (Freon-113) solutions (F-RF.Differing from other perfluoro or polyfluoro radicals, the perfluoro-α-isopropoxyethyl radicals (10) undergo substantial β scission to form perfluoroisopropyl radicals (11) during their lifetime.The ΔHexc. values for the perfluoroacyl peroxides are about 24 kcal mol-1, or about 5 kcal lower than that of the nonfluorinated diacyl peroxides (ca. 29 kcal mol-1).Apparently, the higher relative rates for 3 and 7 are caused by different factors.The latter peroxide (7) decomposes with a more favorable ΔSexc. term, whereas the former (3) decomposes with lower values of both ΔHexc. and ΔSexc..Thus, weakening of the peroxide bond by H bonding of the peroxide oxygen atom with the acidic ω-hydrogen atom seems to be implicated in the decomposition of 3.With a half-life of 81 min at 20 deg C, 3 may become a useful low-temperature initiator for free-radical reactions and polymerization.
- Chengxue, Zhao,Renmo, Zhou,Heqi, Pan,Xiangshan, Jin,Yangling, Qu,et al.
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p. 2009 - 2013
(2007/10/02)
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