broad/bimodal MWD, it also leads to reactor particles with a granular morphology which is inherited from the heterogeneous catalyst component, thus fulfilling the requirement of most of the conventional polymerization processes. In the case of PP, which is overwhelmingly relying on Ziegler–Natta catalysts mostly in the form of MgCl2/TiCl4 with internal electron donor, there however lacks examples of a successful combination of such Ziegler–Natta catalysts with metallocenes to serve the purpose of producing broad/bimodal MWD PP. The reason can be reasonably speculated
as thatthere is much increased difficulty in forming a Ziegler–Natta and metallocene integral that keeps not only the individual catalysts’ polymerization activities but also their stereo-specificities which ensure the formation of isotactic PP.