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Titolo:
STOPPED-FLOW STUDY OF THE INTERACTION OF MGCL2-SUPPORTED ZIEGLER CATALYST WITH (ME)(N)SI(OET)(4-N) - A TOOL FOR UNDERSTANDING THE ACTIVE-SITES PRECURSORS AND THE CORRELATION TO STEREOSPECIFICITY
Autore:
MORI H; SAITO H; YAMAHIRO M; KONO H; TERANO M;
Indirizzi:
JAPAN ADV INST SCI & TECHNOL,SCH MAT SCI,1-1 ASAHIDAI TATSUNOKUCHI ISHIKAWA 923129 JAPAN JAPAN ADV INST SCI & TECHNOL,SCH MAT SCI TATSUNOKUCHI ISHIKAWA 923129JAPAN
Titolo Testata:
Macromolecular chemistry and physics
fascicolo: 4, volume: 199, anno: 1998,
pagine: 613 - 618
SICI:
1022-1352(1998)199:4<613:SSOTIO>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
HIGH-YIELD CATALYSTS; EXTERNAL ALKOXYSILANE DONORS; PROPENE POLYMERIZATION; OLEFIN POLYMERIZATION; NATTA CATALYSTS; RESONANCE; STATES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
H. Mori et al., "STOPPED-FLOW STUDY OF THE INTERACTION OF MGCL2-SUPPORTED ZIEGLER CATALYST WITH (ME)(N)SI(OET)(4-N) - A TOOL FOR UNDERSTANDING THE ACTIVE-SITES PRECURSORS AND THE CORRELATION TO STEREOSPECIFICITY", Macromolecular chemistry and physics, 199(4), 1998, pp. 613-618

Abstract

The active sites precursors on a MgCl2-supported Ziegler catalyst andthe correlation to catalyst stereospecificity were investigated in the initial stage of propene polymerization in terms of the interaction of a variety of ethoxysilanes with the structure (Me)(n)Si(OEt)(4-n). The kinetic study using the stopped-flow technique indicated that the interaction of the catalyst with a variety of ethoxysilanes prevents formation of active sites, and the degree of inhibition depends upon the number of ethoxy groups. It is considered that the values of propagation rate constant on the isospecific active sites an essentially the same regardless of the structure of the ethoxysilane, but the ratio ofthe isospecific active sites to the total number of active sites depends on the number of ethoxy groups. The same tendency in the variationof the activity, the stereospecificity, and the kinetic parameters depending on the number of ethoxy groups attached to a silane atom was observed regardless of whether the ethoxysilanes were treated with the catalyst or with triethylaluminium before polymerization.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 15:18:55