Investigation of Different Ziegler-Natta Catalysts for Propylene Polymerization

Kinetic studies of different MgCl2-supported Ziegler-Natta (ZN) catalysts are carried out during propylene polymerization in slurry phase. Three main procedures for preparing various MgCl2-supported ZN catalysts including grinding, solution and chemical reaction methods are applied and consequently polymerization kinetic profiles areinvestigated. Because of different spatial active sites distribution of various ZN catalysts, individual kinetic nature is shown by any catalyst system. Kinetic profiles of the ZN catalysts synthesized by grinding and solution methods show high initial activity with rapid decay, while that of ZN catalyst prepared with chemical reaction method shows low initial activity with slow decay. In each catalyst system, a plausible model is presented to explain the difference of polymerization kinetic nature based on morphological studies of catalyst and produced polymer particles as well as the effect of catalyst preparation method on distribution of spatial active sites on catalyst surface.

کلیدواژه ها:

Kinetic study ، Zeigler-Natta catalyst ، propylene polymerization ، plausible model