Study of the Effect of Internal Donors Composition in the Titanium–Magnesium Catalysts on the Molecular Weight Distribution of Polyethylene, Polypropylene, and Polyhexene

ABSTRACT New experimental data were obtained on the effect of internal donors composition (di‐n‐butyl phthalate, diethyl 2,3‐diisobutyl succinate and 2‐isopropyl‐2‐isopentyl‐1,3‐dimethoxypropane) in the titanium – magnesium catalysts (TMCs) on the molecular weight distribution of polyethylene, polypropylene, and polyhexene produced over these catalysts during polymerization in the absence and in the presence of hydrogen. These data show the great effect of monomer structure and the presence of hydrogen at the polymerization of α‐olefins on the molecular weight distribution (polydispersity) of polymers. We propose these results are determined by the heterogeneity of active sites with different regiospecificity in the chain transfer reaction with hydrogen at the polymerization of α‐olefins.