Effects of trisobutylaluminium on styrene polymerization with Ni(acac) 2 /MAO/SiO 2 catalyst system activated by methylaluminoxane

Autor:	Luiz Claudio de Santa Maria, Pedro Ivo C. Guimarães, Marcos A. S. Costa, Luis Carlos Ferreira, Mônica Regina Marques Palermo de Aguiar
Rok vydání:	2002
Předmět:	chemistry.chemical_classification Polymers and Plastics Methylaluminoxane General Chemistry Polymer Condensed Matter Physics Catalysis Styrene chemistry.chemical_compound Polymerization chemistry Tacticity Polymer chemistry Materials Chemistry Molecule Molar mass distribution
Zdroj:	Polymer Bulletin. 48:463-468
ISSN:	1436-2449 0170-0839
DOI:	10.1007/s00289-002-0060-9
Popis:	Styrene polymerization with Ni(acac)2/MAO/SiO2 catalytic system was carried out in the presence of methylaluminoxane (MAO), triisobutylaluminum (TIBA) or MAO and TIBA mixture as activators. The catalytic system activated only by TIBA produced polymer with 53% of isotacticity. When the catalytic system was activated by a mixture of MAO and TIBA the polymer isotacticity increases as MAO concentration increases. In this case, the maximum of isotacticity was 59%. The polymer has presented lower molecular weight than the polymer obtained by MAO as activators and the polymer microstructure was not explained by Markov first-order model. In addition, 13C NMR spectra of the polymers obtained after extraction with MEK, have indicated that there are two active sites in this catalytic system.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1c8c6eaddba6c953cd90354fb1ea45ff https://doi.org/10.1007/s00289-002-0060-9 Zobrazit plný text záznamu Full text from SpringerLink