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Characterization of a model Phillips catalyst by mass spectrometry
Author(s) -
Di Croce Pascal Gabriel,
Aubriet Frédéric,
ChétyGimondo Rachel,
Muller JeanFrançois,
Grange Paul
Publication year - 2004
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1375
Subject(s) - chemistry , polymerization , mass spectrometry , fourier transform infrared spectroscopy , polymer , chromium , catalysis , analytical chemistry (journal) , polymer chemistry , silicon , chemical engineering , wafer , organic chemistry , nanotechnology , chromatography , materials science , engineering
A model Phillips catalyst for ethylene polymerization, prepared by spin coating a Cr(III)(Cr(acac) 3 ) precursor on a silicon wafer, was submitted to an oxidative activation. Laser ablation Fourier transform mass spectrometry provided direct information on molecular species at the silicon wafer surface during activation. At 350°C the chromium precursor was degraded, while chromium oxide species were formed. The chromium concentration decreased with temperature. The activated model catalyst was active for ethylene polymerization. Using complementary techniques (Fourier transform infrared spectroscopy, laser desorption/ionization mass spectrometry), the polymer was identified as crystalline polyethylene. After 1 h of polymerization at 160°C, dome‐like structures were observed by atomic force microscopy. Their morphologies were constituted of regions of parallel aligned lamellae of polymer. Copyright © 2004 John Wiley & Sons, Ltd.