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Performance of the Cr[CH(SiMe 3 ) 2 ] 3 /SiO 2 catalyst for ethylene polymerization compared with the performance of the Phillips catalyst

2002; Wiley; Volume: 41; Issue: 3 Linguagem: Inglês

10.1002/pola.10590

1099-0518

Haruhiko Ikeda, Takashi Monoi, Yasuaki Sasaki,

biodegradable polymer synthesis and properties

Abstract The catalysis of a silica‐supported chromium system {Cr[CH(SiMe 3 ) 2 ] 3 /SiO 2 } was compared with a silica‐supported chromium oxide catalyst, the Phillips catalyst (CrO 3 /SiO 2 ). This catalyst was prepared by the calcining of the typical silica support used for the Phillips catalyst at 600 °C and by the support of tris[bis(trimethylsilyl)methyl]chromium(III) {Cr[CH(SiMe 3 ) 2 ] 3 } on the silica. In the slurry‐phase polymerization, this catalyst conducted the polymerization of ethylene at a high activity without organoaluminum compounds as cocatalysts or scavengers. The activity per Cr was about 6–7 times higher than that of the Phillips catalyst. Upon the introduction of hydrogen to the system, the molecular weight of polyethylene did not change with the Phillips catalyst, but it decreased with the Cr[CH(SiMe 3 ) 2 ] 3 /SiO 2 catalyst. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 413–419, 2003