https://repositorio.ufba.br/handle/ri/7742
Tipo: | Artigo de Periódico |
Título: | Study of the catalytic species metallocene/MAO and metallocene/TMA by cyclic voltammetry |
Título(s) alternativo(s): | Journal of Molecular Catalysis A: Chemical |
Autor(es): | Costa, Fábio Gomes Simplício, Lílian M. T. Rocha, Zênis N. da Brandão, Soraia Teixeira |
Autor(es): | Costa, Fábio Gomes Simplício, Lílian M. T. Rocha, Zênis N. da Brandão, Soraia Teixeira |
Abstract: | In this paper, an electrochemical study of the metallocene/methylaluminoxane (MAO) and metallocene/trimethylaluminium (TMA) species is presented. The metallocenes used were [(CH3)2Si(Cp)2ZrCl2] and [(Cp)2ZrCl2]. The evaluation of the Metallocene/MAO and Metallocene/TMA systems was based on the analysis of the redox potentials of the solutions with different Al/Zr molar ratios using acetonitrile as solvent. The results obtained for Al/Zr ratios lower than 30, suggested that in presence of TMA or MAO, the formed monomethylated species are [(L)ZrIV(CH3)Cl], L = cyclopentadienyl (Cp)2 or (CH3)2Si(Cp)2. For Al/Zr molar ratios higher than 30, the results obtained in TMA presence are in agreement with the formation of the species [(L)ZrIV(CH3)( -CH3)Al(CH3)2]+, while in MAO presence the ionic pair,[(L)ZrIVCH3]+[MAOCl]−, is formed. There’s a general agreement that these are active species in olefin polymerization. |
Palavras-chave: | Zirconocenes Polymerization Ethylene Cyclic voltammetry |
Editora / Evento / Instituição: | Elservier |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/7742 |
Data do documento: | 2004 |
Aparece nas coleções: | Artigo Publicado em Periódico (Química) |
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1-s2.0-S1381116903007258-main.pdf Restricted Access | 168,81 kB | Adobe PDF | Visualizar/Abrir Solicitar uma cópia |
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