Artículo
Comparative study of propylene polymerization using Me2Si(RInd)2ZrCl2/SiO2-SMAO/ AlR3 and Me2Si(RInd)2ZrCl2/MAO (R = Me, H)
Franceschini, F. C.; Tavares, T. T. da R.; dos Santos, J. H. Z.; Soares, J. B. P.; Ferreira, María Luján
Fecha de publicación:
23/03/2007
Editorial:
Elsevier
Revista:
Polymer
ISSN:
0032-3861
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
A mechanistic analysis of propylene polymerization was performed, in which the catalyst system was Me2Si(R1Ind)2ZrCl2/SMAO/AlR 3 2 (in situ supported catalyst onto MAO-modified silica) or Me2Si(R1Ind)2ZrCl2/MAO (homogeneous), where R1 = H or CH3, cocatalyzed by AlR3 2 = TEA (triethylaluminum), IPRA (isoprenylaluminum), or TIBA (triisobutylaluminum). The catalyst activity of the homogeneous system Me2Si(2-Me-Ind)2ZrCl2/MAO was almost 8 times higher than that observed for Me2Si(Ind)2ZrCl2/MAO (38 vs 4.6 kg PP/g cat h), while the polypropylene molar mass was 3 times higher (Mw: 93 vs 34 kg/mol). Conversely, the in situ supported systems Me2Si(Ind)2ZrCl2/SMAO/AlR3 and Me2Si(2-Me-Ind)2ZrCl2/SMAO/AlR 3 showed similar activities, ranging from 0.2 to 1.5 kg PP/g cat h. The molar mass of the resulting polymers prepared using the in situ procedure was dependent on the AlR3 nature and on the Al/Zr ratio. Generally, the heterogeneous catalysts produced PP with higher molecular weights than that obtained with homogeneous ones. The influence of the alkylaluminum, used as the cocatalyst, on the chain-transfer termination reaction to the alkyl compound was evident from the activity and the molecular weight of the produced polymers.
Palabras clave:
In Situ Immobilization
,
Metallocene Catalyst
,
Polypropylene
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Identificadores
Colecciones
Articulos(PLAPIQUI)
Articulos de PLANTA PILOTO DE INGENIERIA QUIMICA (I)
Articulos de PLANTA PILOTO DE INGENIERIA QUIMICA (I)
Citación
Franceschini, F. C.; Tavares, T. T. da R.; dos Santos, J. H. Z.; Soares, J. B. P.; Ferreira, María Luján; Comparative study of propylene polymerization using Me2Si(RInd)2ZrCl2/SiO2-SMAO/ AlR3 and Me2Si(RInd)2ZrCl2/MAO (R = Me, H); Elsevier; Polymer; 48; 7; 23-3-2007; 1940-1953
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