A kinetic argument for a quasi‐living polymerization of propene with a MgCl₂‐supported catalyst

Lifetime of growing polymer chain in stopped-flow propene polymerization using pre-treated Ziegler catalysts

“…The method seems to be most suitable for the kinetic study of olefin polymerization with Ziegler catalysts, because a quasi-living polymerization stage can be attained, where the states of the active sites are constant without a time-dependent change and the chain-transfer reaction can be effectively negligible. However, our attention was mainly focused on the propene polymerization with monoester-type supported catalysts [13][14][15][16][17][18][19][20][21][22] and an internal donor-free supported catalyst 23,24) . During the first stage of the experiment, therefore, the initial polymerization behavior of propene catalyzed by the monoester-type supported catalyst was compared with that using the diester-type supported catalyst.…”

“…The stopped-flow polymerization of propene and the estimation of the kinetic parameters were conducted using the method developed by Keii and Terano 13,14) . A typical procedure for the polymerization is as follows.…”

Specific Roles of Al‐Alkyl Cocatalyst in the Origin of Isospecificity of Active Sites on Donor‐Free TiCl4/MgCl2 Ziegler‐Natta Catalyst

“…[9,[14][15][16]32] The disadvantage of these approaches is connected with the continuously varying states of active sites accompanied with chain transfer and deactivation during polymerization. The stopped-flow technique, [38] by which a quasi-living polymerization process can be realized within an extremely short period (ca. 0.2 s), has been proven to be one of the most powerful methods in heterogeneous Ziegler-Natta catalysis for studying the nature of the active sites and elucidating the olefin polymerization mechanism [39] as well as developing a series of novel block copolymers.…”

Stopped-Flow Techniques in Ziegler Catalysis

“…[1] Compared with a homogeneous stopped-flow polymerization system connected with a spectroscopic detector, this polymerization system is heterogeneous, and the catalyst particles can facilitate the mixing process in slurry flow conditions. Furthermore, the information concerning the active sites and the polymerization procedures was obtained by direct analysis of the polymer produced at the initial polymerization stage, using the original apparatus described in the next section.…”