Ethylene Polymerization with Supported Vanadium-Magnesium Catalyst: Number of Active Centers and Propagation Rate Constant
Macromolecular Chemistry and Physics
, E-ISSN: 1521-3935
Matsko Mikhail A.
Bukatov Gennadii D.
Mikenas Tatiana B.
Zakharov Vladimir A.
Boreskov Institute of Catalysis, Prospect Academika Lavrentieva 5, Novosibirsk 630090, Russia
The data on the number of active centers in the ethylene polymerization with highly active supported
vanadium-magnesium catalyst (130 kg-PE/g-V N h N bar) were obtained by using 14CO as a radioactive inhibitor.
The number of active centers was found to attain 0.06 mol/mol-V and the propagation rate constant equaled
2.2 N 104 L/mol N s (808C). The effect of reversible deactivation of the catalyst in ethylene polymerization in the
presence of hydrogen was studied. It was found that a part of the active centers containing vanadium-polymer bonds
transforms to a temporary inactive (dormant) state during the polymerization in presence of hydrogen that may
explain the catalyst deactivation. As hydrogen is removed from the reaction medium, these centers transform to the
active state again