کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5204809 1381972 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stability of polyynes in air and their degradation by ozonolysis
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Stability of polyynes in air and their degradation by ozonolysis
چکیده انگلیسی
Polyyne solutions in n-hexane or other aliphatic hydrocarbons having C6H2, C8H2 and C10H2 as main components were found to be unstable at relatively high concentration (≈10−2 M) and to separate in few hours a brown precipitate. This phenomenon does not occur in more dilute solutions. The precipitate recovered from the mentioned solutions was analysed by FT-IR spectroscopy and thermogravimetry and found to be constituted by polyyne chains crosslinked and oxidized by oxygen resembling in some way the product obtained by photolysing acetylene in water solution and in presence of air. Polyynes react very quickly with ozone producing as main product polymeric ozonides which are insoluble in hydrocarbons and which have been studied with FT-IR spectroscopy. The oxidized nature of the chains highly crosslinked by ozonides, peroxide and oxygen bridges has been confirmed. The oxidized polyyne fraction remaining in solution after ozonolysis was studied by electronic absorption spectroscopy and by liquid chromatography. Extensive chain breaking was found as expected although some degree of unsaturation was preserved even in the final oxidized products.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 91, Issue 2, February 2006, Pages 317-323
نویسندگان
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