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Addition of Lewis bases and acids. Effect on α‐olefins polymerization with soluble metallocenes, 1 Ethylene
Author(s) -
Belelli Patricia Gabriela,
Ferreira María Luján,
Damiani Daniel Eduardo
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20000801)201:13<1458::aid-macp1458>3.0.co;2-1
Subject(s) - methylaluminoxane , chemistry , lewis acids and bases , polymer chemistry , polymerization , metallocene , ethylene , catalysis , toluene , polymer , solvent , coordination polymerization , solution polymerization , photochemistry , organic chemistry
In Part 1 of this series the soluble system rac ‐EtInd 2 ZrCl 2 /methylaluminoxane (MAO) was studied in ethylene polymerization with additives. Lewis acids and bases such as AlCl 3 and ethyl benzoate (EB) were used to evaluate their effects on polymerization kinetics, catalyst activities, and polymer properties. The results obtained showed a clear trend to improve the performance when AlCl 3 was added. The Lewis base might be acting in different ways on the active sites. The activity is strongly decreased with EB. To further elucidate some of the different aspects of metallocene activation, a UV/Visible spectroscopic study was carried out, with toluene as solvent. It was possible to correlate the catalytic activity with AlCl 3 as additive to changes in the intensity of the ligand to metal charge transfer (LMCT) bands of EtInd 2 ZrCl 2 when MAO/AlCl 3 was the coactivator.