Modifications of the active sites distribution in the Ziegler-Natta polymerization of propylene using Lewis acids
Heterogeneous Ziegler-Natta precatalysts (with phthalate as internal donor) were modified by treatments with various Lewis acids (MCln with M = Ga, Sn, Si, and Sb and n = 3, 4, or 5) before their use in the polymerization of propylene. If performed on previously "detitanated" precatalysts,...
Gespeichert in:
Veröffentlicht in: | Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2010-06, Vol.48 (12), p.2631-2635 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Heterogeneous Ziegler-Natta precatalysts (with phthalate as internal donor) were modified by treatments with various Lewis acids (MCln with M = Ga, Sn, Si, and Sb and n = 3, 4, or 5) before their use in the polymerization of propylene. If performed on previously "detitanated" precatalysts, treatments with SnCl₄ and SiCl₄ lead to a slight activation but especially to an increase of the tacticity whereas GaCl₃ and SbCl₅ treatments deactivate the catalyst. The modification method applied to conventional unmodified precatalysts gave similar trends. A significant increase of tacticity (and/or of Tm) and a narrowing of the molecular weight distribution were observed in the case of SnCl₄ and SiCl₄ treatments. |
---|---|
ISSN: | 0887-624X 1099-0518 1099-0518 |
DOI: | 10.1002/pola.24043 |