Polymerization of ethylene with the (C5H5)4Zr-methylaluminoxane soluble catalytic system

Mechanism of the interaction of components in the metallocene catalytic systems containing titanium and zirconium tetracyclopentadienyls and methylaluminoxane

“…The following main conclusions can be drawn after the consideration of the regularities of the polymerization and hex-1-ene under the action of soluble catalytic systems containing (C 5 H 5 ) 4 Zr and (C 5 H 5 ) 4 Ti presented in [28,29]. We will use these conclusions in the further study of the polymerization mechanism.…”

“…Nevertheless, the S-shaped curves of ethylene absorption in the case of polymerization in the presence of the (C 5 H 5 ) 4 Zr-MAO system indicates a more complicated mechanism of AS formation in this system compared to the (C 5 H 5 ) 4 Ti-MAO system. (2) The reaction rate of ethylene and hex-1-ene polymerization in the presence of the (C 5 H 5 ) 4 Zr-MAO system has the order [1 with respect to the monomer concentration [28], which also indicates a complicated mechanism of AS formation involving the monomer.…”

“…(1) The absence of an induction period of ethylene polymerization in the presence of the catalytic systems (C 5 H 5 ) 4 Zr-MAO and (C 5 H 5 ) 4 Ti-MAO indicates a high rate of formation of the active sites of the polymerization in both systems [28]. Nevertheless, the S-shaped curves of ethylene absorption in the case of polymerization in the presence of the (C 5 H 5 ) 4 Zr-MAO system indicates a more complicated mechanism of AS formation in this system compared to the (C 5 H 5 ) 4 Ti-MAO system.…”

“…The known procedures [3,28] were used to synthesize (C 5 H 5 ) 4 Zr and (C 5 H 5 ) 4 Ti. Trimethylaluminum (TMA) and MAO (Aldrich) were used as solutions in toluene with a concentration of 1-2 mol/L without additional purification.…”