Study of molecular size in ethylene-propene copolymerization with zirconocene and hafnocene catalysts

Naofumi Naga, Yoshiaki Ohbayashi, Kooji Mizunuma

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Ethylene-propene copolymerization was carried out with Cp2MCl2 (Cp = cyclopentadienyl), rac-Et(Ind)2MCl2, rac-Me2Si(Ind)2MCl2 (Et = ethylene, Me2Si = dimethylsilyl, Ind = indenyl, M = Zr or Hf)/methylaluminoxane. In the case of using ansa-hafnocenes, the minimum molecular size (extended chain length) of ethylene-propene copolymer was obtained at about 50 mol-% of propene content in the copolymer. The polymerization activity decreased with increase of propene feed ratio in non-bridged non-specific metallocenes. Higher polymerization activities were observed for the copolymerization compared to ethylene and propene homo-polymerization with ansa-isospecific metallocenes. The factor of molecular size lowering was studied by the chain propagation and chain transfer reaction.

Original languageEnglish
Pages (from-to)837-851
Number of pages15
JournalMacromolecular Rapid Communications
Volume18
Issue number9
DOIs
Publication statusPublished - 1997 Sep
Externally publishedYes

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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