کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
67300 48475 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Comparison of olefin polymerization behavior of sterically crowded tris(pyrazolyl)borate group 4 metal complexes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Comparison of olefin polymerization behavior of sterically crowded tris(pyrazolyl)borate group 4 metal complexes
چکیده انگلیسی

The ethylene polymerization and ethylene/α-olefin copolymerization behavior of the sterically crowded tris(pyrazolyl)borate group 4 metal complexes TpMs*TiCl3 (1, TpMs* = HB(3-mesitylpyrazolyl)2(5-mesitylpyrazolyl)−), {K[TpMs*TiCl3]}2 (2), TpMs*TiCl2(O-2,4,6-tBu3-Ph) (3), TpMs*ZrCl3 (4), TpMsZrCl3 (5, TpMs = HB(3-mesitylpyrazolyl)3−), and TpMs*HfCl3 (6) were studied with dried-MAO activation in toluene solution. These catalysts all produce very high molecular weight (Mv > 106) linear polyethylene. Zirconium catalyst 5 excels in productivity in ethylene homopolymerization and ethylene/1-hexene copolymerization, molecular weight, and hexene incorporation ability. Catalyst 5 produces moderately alternating ethylene/1-hexene copolymer (41 mol% hexene) with ultra-high molecular weight (Mw = 1.3 × 106), narrow molecular weight distribution (Mw/Mn = 2.2) and narrow composition distribution with high efficiency.

The olefin polymerization performance of sterically crowded group 4 (tris-pyrazolylborate)MX3/dried-MAO catalysts was investigated. Diverse behavior is observed for complexes with different metals, oxidation states and ligands. TpMsZrCl3 (5, TpMs = HB(3-mesitylpyrazolyl)3−) produces moderately alternating ethylene/1-hexene copolymer (41 mol% hexene) with ultra-high molecular weight (Mw = 1.3 × 106, Mw/Mn = 2.2), and uniform composition distribution with high efficiency at 80 °C in toluene.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Catalysis A: Chemical - Volume 282, Issues 1–2, 3 March 2008, Pages 107–116
نویسندگان
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