Efficient Molecular Weight Control with Trialkylaluminum in Ethylene/Norbornene Copolymerization by [Ph2C(Flu)(3-MeCp)]ZrCl2/Methylaluminoxane Catalyst

✍ Scribed by Tomoyuki Tada; Zhengguo Cai; Yuushou Nakayama; Takeshi Shiono

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 189 KB
• Volume: 211
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.201000172

✦ Synopsis

Abstract

Ethylene/norbornene copolymerizations were conducted with [Ph~2~C(Flu)(3‐RCp)]ZrCl~2~ [R: Me (1) or Me~3~Si (2)], which give alternating EN copolymers. The activity of 1 in the absence of R~3~Al was approximately twice that of 2 and increased further upon addition of R~3~Al. Et~3~Al increased the activity most effectively, and the $\overline {M} _{{\rm n}} $ of the produced polymer decreased from 100 000 to 25 000 g · mol^−1^. On the other hand, the $\overline {M} _{{\rm n}} $ value increased upon addition of ^i^Bu~3~Al from 100 000 to 209 000 g · mol^−1^ accompanied by an ≈2.5‐fold increase of activity. Consequently, 1 was found to be one of the most promising complexes for the synthesis of alternating EN copolymers, of which $\overline {M} _{{\rm n}} $ value was efficiently controlled by the kind and the amount of R~3~Al added.

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