A New Supported Zirconocene Catalyst for Ethylene Polymerization

Abstract

Metallocene catalysts enable the structure of polymers to be tailored in a way which has not been reached before. However, they are more active than the conventional Ziegler — Natta catalysts only as homogeneous metalocene systems, a fact that has essentially restricted their use to industrial processes producing polymers in solution. Modern polymerization processes are solvent free slurry (with liquid monomer) or gas phase processes. To use metallocene catalysts in these modern processes, it is necessary to convert them to heterogeneous catalysts [1, 2]. However, problems have appeared chiefly concerning the activity of the supported catalysts, because heterogeneous metallocene catalysts are much less active than supported Ziegler—Natta catalysts [3,4]. Most solid systems that have been reported cause a dramatic decrease in the activity when compared with the corresponding metallocenes in the solution. Generally, developing of heterogeneous catalyst, with the metallocene as active component supported on the surface of a solid carrier, is the point of extreme interest of resent years.