Effect of the silica texture on grafting metallocene catalysts - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Molecular Catalysis Année : 2007

Effect of the silica texture on grafting metallocene catalysts

(1) , , (2) , , (3) , (4) , (4)
1
2
3
4
Fernando Silveira
Gilvan P. Pires
  • Fonction : Auteur
Cristiane F. Petry
  • Fonction : Auteur
EDF
Dirce Pozebon
  • Fonction : Auteur
Arnaud Rigacci

Résumé

A series of hybrid supported catalysts was prepared by sequentially grafting Cp2ZrCl2 and (nBuCp)2ZrCl2 (1:3 ratio) onto synthesized xerogel, aerogel and commercial silicas. Supports and catalysts were characterized by Rutherford backscattering spectrometry, energy-dispersive X-ray scanning electron microscopy, atomic force microscopy and nitrogen adsorption. Grafted metal content laid between 0.15 and 0.5 wt.% Zr/SiO2. All the systems were shown to be active in ethylene polymerization with methylaluminoxane as the co-catalyst. Catalyst activity and molecular weight were shown to depend on the textural characteristic of the silicas, namely grain size and pore diameter. The highest activity in ethylene polymerization (ca. 5310 kg PE mol Zr−1 h−1) was obtained with the supported catalyst using commercial silicas with average particle size around 50 μm. Particles with sizes of 80–90 μm obtained less activity. Resulting polymers were characterized by gel permeation chromatography and differential scanning calorimetry.

Dates et versions

hal-00196732 , version 1 (13-12-2007)

Identifiants

Citer

Fernando Silveira, Gilvan P. Pires, Cristiane F. Petry, Dirce Pozebon, Fernanda C. Stedile, et al.. Effect of the silica texture on grafting metallocene catalysts. Journal of Molecular Catalysis, 2007, 265 (1-2), pp.167-176. ⟨10.1016/j.molcata.2006.10.008⟩. ⟨hal-00196732⟩
54 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook Twitter LinkedIn More