کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190527 1381208 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Polymerization of norbornene using novel palladium carboxylate/boron trifluoride etherate catalyst system
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Polymerization of norbornene using novel palladium carboxylate/boron trifluoride etherate catalyst system
چکیده انگلیسی
The vinyl polymerization of norbornene with Pd(carboxylate)2/BF3OEt2 catalyst system has been investigated by varying the molar cocatalyst/metal ratio, the norbornene/metal ratio, the metal concentration and the reaction temperature. The effects on the catalyst activity were explained on the basis of complexation equilibrium for the active homogeneous complex. A “particular” activity of 154 100 kg NB per mole Pd for an hour has been achieved at B/Pd = 25 and 25 °C. The molecular weights Mw from 77 700 to 293 800 g/mol and glass transition temperatures Tg from 240 to 262 °C were observed for the representative samples of polynorbornene. The molar mass distribution indicates a single-site, highly homogeneous character of the active catalyst species. Catalytic activity and polymer molecular weight can be controlled by varying the reaction parameters over a wide range. NMR and IR spectroscopic studies of the polymer showed 2,3-enchained repeating units of polymer backbone with low diisotacticity. The simplicity of catalyst system composition might be of industrial importance.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 26, 8 December 2006, Pages 8474-8479
نویسندگان
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