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The influence of the preparing conditions of SiO 2 supported Cp 2 ZrCl 2 catalyst on ethylene polymerization
Author(s) -
De Fátima V. Marques Maria,
Conte Anunciata
Publication year - 2002
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.11166
Subject(s) - metallocene , methylaluminoxane , gel permeation chromatography , calcination , polyethylene , materials science , catalysis , differential scanning calorimetry , ethylene , polymer chemistry , polymerization , molar mass distribution , polymer , zirconium , chemical engineering , nuclear chemistry , chemistry , organic chemistry , composite material , metallurgy , physics , engineering , thermodynamics
In this work, ethylene was polymerized by using Cp 2 ZrCl 2 supported on silica pretreated with methylaluminoxane (MAO) as the catalyst system. The influence of the conditions for the preparation of the heterogeneous catalyst, such as temperature, washing method of the catalytic solid, MAO and metallocene concentration in the support treatment, time of MAO, and metallocene immobilization on the support, type of alkylaluminum used in the support pretreatment, and calcination temperature of the support were investigated. Aluminum and zirconium content fixed on the silica surface were determined by inductively coupled plasma emission spectroscopy. Polymer characteristics were determined by gel permeation chromatography and differential scanning calorimetry. According to the results, the activity of some supported catalysts were far higher than with the homogeneous system. Moreover, polyethylene with very high molecular weights were also obtained and with molecular weight distribution larger than those produced with the homogeneous precursor. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2054–2061, 2002