Kinetics of Olefin Polymerization and Active Sites of Heterogeneous Ziegler–Natta Catalysts
||Polyolefins: 50 years after Ziegler and Natta I. Polyethylene and Polypropylene
Springer Heidelberg. 2013.
257 c. ISBN 9783642408076.
||Active site number, Kinetic features, Mechanism, Metallorganic catalysts, Olefin polymerization
Semenov Institute of Chemical Physics RAS
Boreskov Institute of Catalysis SB RAS
Kinetic investigations of olefin polymerization with Ziegler–Natta (ZN) catalysts provide information for understanding the mechanism of these reactions and are also necessary for development of industrial productions of polyolefins. In this chapter, the main kinetic features of olefin polymerization with heterogeneous ZN catalysts are considered as well as problems such as a deviation from the linear dependence of the rate of polymerization on monomer concentration, the hydrogen effect in ethene and propene polymerizations, and the comonomer effect, the natures of which are not yet completely clear and are discussed in the literature. For analysis of the kinetics and mechanism of olefin polymerization, data on the number of active centers and propagation rate constants are important. The main methods for determination of these kinetic parameters are discussed in this chapter.
Data on the number of active centers in ZN catalysts of different composition are presented. On the base of these kinetic data, the hydrogen effect and the heterogeneity of active centers at propylene polymerization over ZN catalysts are analyzed.