Copolymerization of Ethylene with Diene Comonomers using Bis (2-PhInd) Zr Cl2 as Metallocene Catalyst: ΙΙΙ. Kinetic study

The comonomer effect on the copolymerization of ethylene with two different kinds of diene monomers has been investigated using metallocene/methylaluminoxane (MAO) homogeneous catalytic system in this work. Some experiments have been done in order to scrutinize the role of donor/acceptor interactions on the coordination catalyst site activity and the comonomer steric effects on the polymerization kinetic. 2-methyl-1,3-butadiene (isoprene) and 5-ethylidene-2-norbrnene (ENB) have been examined in order to distinguish their influences on the catalyst activity. In the case of the former, it has been shown that, according to its Lewis acidity the formation of stable active center-ISP complexes in high comonomer loadings may result in severe catalyst poisoning. In spite of this, it has been illustrated that, in lower diene/Zr molar ratios a significant catalyst activity enhancement is observed. In the later, i.e. ENB the catalyst activity has not been altered by changing the diene/Zr molar ratio meaning fully.