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.
|Number of pages||15|
|Journal||Macromolecular Rapid Communications|
|Publication status||Published - 1997 Sep|
ASJC Scopus subject areas
- Materials Chemistry
- Polymers and Plastics