The development of stereoerrors during the homo- and copolymerization of propylene using C-2-symmetric metallocene catalysts - A cautionary note

摘要

A recent paper described the development of atactic sequences during the copolymerization of propylene and 1-pentene using the C-2-symmetric metallocene catalyst rac-dimethylsilyl-bis(2-methylbenz(e)indenyl) zirconium dichloride. We have found similar stereoerrors, and showed that atactic material could in fact be extracted from the material, indicating that the catalyst in question had probably isomerized in solution, leading to a mixture of isotactic and atactic polymers.