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Master's Dissertation
DOI
10.11606/D.46.2001.tde-30102008-093923
Document
Author
Full name
Alessandra de Souza Maia
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2001
Supervisor
Committee
Oliveira, Wanda de (President)
Frem, Regina Célia Galvão
Kawano, Yoshio
Title in Portuguese
Estudo de alguns compostos organolantanídeos como catalisadores na reação de polimerização de etileno
Keywords in Portuguese
Compostos organolantanídeos
Metilaluminoxano
Polimeração de etileno
Abstract in Portuguese
Neste trabalho, estudaram-se a síntese, a caracterização e a atividade catalítica na polimerização do etileno dos compostos organolantanídeos contendo ou não os ligantes pirazol (HPz) ou trifenilfosfina (PPh3), visando contribuir para a aplicação de organolantanídeos como catalisadores na polimerização de olefinas. A síntese dos compostos organolantanídeos foi feita em etapas, partindo-se dos brometos ou cloretos de lantanídeos anidros. Na primeira etapa, os compostos organolantanídeos LnX2Cp, X = Cl- ou Br-, Cp = ciclopentadienil e Ln = Sm, Tb, foram obtidos pela reação de LnCl3 ou LnBr3 anidros com NaCp em tetrahidrofurano, com razão molar de 1:1 (Ln:NaCp). A segunda etapa envolveu a sintese de SmBr2Cp(HPz)2, TbBr2CpHPz, LnCl2CpHPz, Ln = Sm, Tb e LnX2CpPPh3, X = Cl-, Br- e Ln = Sm, Tb, pela reação de LnX2Cp com os ligantes HPz ou PPh3 em tolueno, com razão molar apropriada. A análise elementar, a termogravirnetria, espectroscopia na região do infravermelho e a ressonância magnética nuclear de 1H foram as técnicas utilizadas para caracterizar os compostos. Estas classes de compostos organolantanídeos apresentaram atividade catalítica da ordem de 4,0 gPE mmolLn-1h-1bar-1, a polimerização do etileno (3 bar, 70°C) com a relação Al/Ln de 2000, usando como co-catalisador o polimetilaluminoxano. O polietileno obtido apresentou grau de cristalinidade de 39%.
Title in English
Study of some organolanthanide compounds as catalysis of ethylene polymerization reaction
Keywords in English
Ethylene polymerization
Methylaluminoxane
Organolanthanide compounds
Abstract in English
In attempt to contribute to the application of organolanthanides as catalysts for olefin polymerization, we report the synthesis, characterization and catalytic activity in ethylene polymerization ofthe organolanthanide compounds containing or not the ligands triphenylphosphine (PPh3) and pyrazole (HPz). The synthesis of the organolanthanide compounds was performed in steps, from lanthanide chlorides or bromides. In the first step the organolanthanide compounds LnX2Cp, X = Cl- or Br-, Cp = cyclopentadienyl and Ln = Sm, Tb, were prepared by the reaction of anhydrous LnCl3 or LnBr3 with NaCp in tetrahydrofuran, with molar ratio of 1:1 (Ln:NaCp). The second step involved the synthesis of SmBr2Cp(HPz) 2, TbBr2CpHPz, LnCl2CpHPz, Ln = Sm, Tb and LnX2CpPPh3, X = Cl-, Br- and Ln = Sm, Tb, by the reaction of LnX2Cp with the HPz or PPh3 ligands in toluene, with appropriate molar ratios. Elemental analysis, thermogravimetry, infrared spectroscopy and 1H NMR were the techniques used to charcterize the compounds. These classes of organolanthanide compounds showed catalytic activity ca. 4.0 gPE mmolLn-1h-1bar-1, in ethylene polymerization (3 bar, 70°C) with Al/Ln ratio of 2000, using polymethylaluminoxane as cocatalyst. the resulting polyethylene presented crystallinity of 39%.
 
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Publishing Date
2008-11-03
 
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