Comparison of Olefin Polymerization Processes with Metallocene Catalysts

✍ Scribed by Walter Kaminsky; Fabian Müller; Oliver Sperber

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 176 KB
• Volume: 290
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200400285

✦ Synopsis

Abstract

Summary: Solution and gas phase processes of the polymerization of ethene are compared using new types of pentalenyl bridged ansa‐metallocenes such as [Me~3~Pen(Flu)]ZrCl~2~. As of the bridge, the catalyst system is remarkable thermostable up to 105 °C and a deactivation of the metallocene on the silica support can be suppressed. Compared to the non‐supported catalyst in a solution process, the application of the heterogenized system in a gas phase process leads to a decrease in activities while molar masses of the polyethenes are similar. Due to a higher degree of short chain branches of 20–30 per 1 000 carbon atoms instead of 10–17, the melting temperatures are 10 °C lower than those for polymers obtained in the solution process.

Basic structure of the here used pentalenyl bridged ansa‐metallocenes.

magnified imageBasic structure of the here used pentalenyl bridged ansa‐metallocenes.