Effects of low hydrogen partial pressures on propylene polymerization by Cp*TiMe2(μ-Me)B(C6F5)3
✍ Scribed by Sean W. Ewart; Michelle A. Parent; Michael C. Baird
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 104 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0887-624X
No coin nor oath required. For personal study only.
✦ Synopsis
Polymerization of propylene by Cp*TiMe 2 (-Me)B(C 6 F 5 ) 3 in the presence of increasing partial pressures of H 2 results in ever decreasing polymer molecular weights, which is consistent with the hydrogenolytic chain transfer processes involving metal-polymer bonds in many heterogeneous and homogeneous systems. However, catalytic activities are not significantly increased as the extent of hydrogenolysis increases, unlike metallocene catalyst systems in which the H 2 reacts primarily with dormant catalytic sites containing propylene 2,1-insertion products. It was shown previously that monocyclopentadienyl systems do not become seriously deactivated following 2,1 insertions, and thus hydrogenolysis does not result in enhanced activities.