An insight into the chain-propagation mechanism of propylene polymerization catalyzed by traditional Ti-based Ziegler-Natta catalysts in view of recently developed catalysts

The propagation mechanism of 1-alkenes, especially propylene, for newly developed catalysts such as metallocene catalysts and bis(phenoxy-amine) zirconium-based catalysts and traditional Ti-based Ziegler-Natta catalysts, and the relationship between the structure of the catalyst and the structure of polyolefins produced, was reviewed. We believe that the propagation mechanism of 1-alkenes, especially propylene, for traditional Ti-based heterogeneous catalysts and the relationship between the structure of the catalyst and the structure of polyolefins produced is elucidated more explicitly with metallocene catalysts and bis(phenoxy-amine)zirconium-based catalysts as reference.