Structure–performance relationship in Ziegler–Natta olefin polymerization with novel core–shell MgO/MgCl2/TiCl4 catalysts

Abstract

The impact of support architectures on the olefin polymerization performance of heterogeneous Ziegler–Natta catalysts has been scarcely understood due to the complexity of pore system and the fragmentation-induced structural changes during polymerization. In this communication, a series of novel core–shell MgO/MgCl2/TiCl4 catalysts were synthesized by utilizing poreless single-crystal MgO nanoparticles as a non-fragmentable core material. Employing these catalysts, we have successfully established a structure–performance relationship (SPR) that the propylene polymerization activity is perfectly proportional to the catalyst surface area for the first time. On the other hand, polymer properties were found to be decided by active site natures independently of the surface area.