Influence of the type of the bridge on the activity of supported metallocene catalysts in ethylene polymerization

Metallocene catalysts open new field in polymerization of olefins [1, 2]. These catalysts show single site active center and make it possible to design the structure of polymerprecisely. In comparison with conventional Ziegler-Natta catalysts, which have plural active sites and producedpolymers with broad MWD, metallocene catalysts have much higher activity and lower polydispersity The immobilization of metallocene/MAO systems on silica supports is generallycarried out by contacting the metallocene with a MAO impregnated support, or by first contacting metallocene and MAO to generate the active species before immobilization on the support [3]. In present study, the second approach has beeninvestigated