Effect of the zeolite HY-support on the monoalkene polymerization by group IV metallocenes

“Bound but Not Gagged”Immobilizing Single-Site α-Olefin Polymerization Catalysts

“…In comparison, the report by Janiak and Rieger on Ind 2 ZrCl 2 activated by MAO/SiO 2 and in solution resulted in waxy aPP for both systems . Isotactic enrichment of polypropylene has, however, been observed when the aspecific precatalyst Ind 2 ZrCl 2 is immobilized onto zeolite HY previously contacted with MAO . A more pronounced example of the effect that grafting can have on stereocontrol can be seen when Me 2 Si(Flu)(Cp)ZrCl 2 is precontacted with silica prior to activation by MAO.…”

Hybrid zeolitic-mesostructured materials as supports of metallocene polymerization catalysts

“…Previous studies have described the anchorage of metallocenes on zeolites [11][12][13][14][15][16][17][18] and mesoporous materials like MCM-41 and SBA-15 [19][20][21][22][23][24][25]. The results evidenced that textural properties of the ordered microporous and mesoporous supports influence the structure of the supported metallocenes and, therefore their catalytic activity.…”

New iron containing mesoporous catalysts

“…From the economical point of view, immobilisation of metallocene compounds is also profitable because it leads to the decrease of the large excess of expensive methylaluminoxane (MAO), which is used as co-catalyst. Besides, only the application of heterogeneous catalysts makes the uniform polymer particles and bulk density possible [3].…”