Investigation of a fine-grain MgCl2-supported Ziegler catalyst by stopped-flow propene polymerization: Model for the formation of active sites induced by catalyst fragmentation during polymerization

✍ Scribed by Hideharu Mori; Masaki Yoshitome; Minoru Terano

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 502 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021981018

✦ Synopsis

Abstract

A fine‐grain catalyst, as a model of catalyst fragmentation in the course of polymerization, was prepared by grinding an original MgCl~2~‐supported Ziegler catalyst. In order to clarify the nature of the active sites generated after catalyst fragmentation, the kinetic parameters for propene polymerization with both catalysts were estimated using the stopped‐flow method. The active sites concentration of the fine‐grain catalyst was higher than that of the original MgCl~2~‐supported catalyst, indicating that the grinding treatment induced the formation of new active sites. However, the propagation rate constant and stereoregularity of polypropene remained unaffected. This is an indication that the nature of the active sites formed after the grinding treatment was the same as that of active sites on the original MgCl~2~‐supported catalyst.