التفاصيل البيبلوغرافية
| العنوان: |
The role of alkoxysilanes in propylene polymerization catalysis. A study of model Ti(Oi‐C3H7)4‐Al(C2H5)2Cl/Mg(C4H9)2 catalyst system. |
| المؤلفون: |
Kissin, Yury V, Rishina, Laura A, Lalayan, Svetlana S, Krasheninnikov, Vadim G |
| المصدر: |
Polymer International; Jul2023, Vol. 72 Issue 7, p655-663, 9p |
| مصطلحات موضوعية: |
ZIEGLER-Natta catalysts, INDUSTRIAL chemistry, PROPENE, ALKOXYSILANES, CATALYSTS, POLYMERIZATION |
| مستخلص: |
The article describes the modifying effect of methylcyclohexyldimethoxysilane (CH3)(cyclo‐C6H11)Si(OCH3)2 in propylene polymerization reactions with a pseudo‐homogeneous catalyst system: Ti(Oi‐C3H7)4‐Al(C2H5)2Cl/Mg(C4H9)2. This catalyst system is a convenient model for the analysis of modifier effects (effects of 'external donors') in supported Ziegler–Natta polymerization catalysts of the fourth generation. A combination of chromatographic, spectroscopic and calorimetric data for crystalline and amorphous fractions of polypropylene prepared in the presence of the silane shows that it has a dual modification effect: (i) the silane is a potent poison of stereo‐aspecific active centers in the catalyst (the centers producing amorphous polypropylene fraction) and (ii) silane molecules coordinate at isospecific centers in the catalyst and changes their nature: the centers produce isotactic polypropylene of higher molecular weight and a higher isotacticity level. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |