Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Control of stereoerror formation with high-activity "dual-side" zirconocene catalysts: A novel strategy to design the properties of thermoplastic elastic polypropenes
Autore:
Dietrich, U; Hackmann, M; Rieger, B; Klinga, M; Leskela, M;
Indirizzi:
Univ Ulm, Dept Mat & Catalysis, D-89069 Ulm, Germany Univ Ulm Ulm Germany D-89069 Dept Mat & Catalysis, D-89069 Ulm, Germany Univ Helsinki, Dept Inorgan Chem, FIN-00014 Helsinki, Finland Univ Helsinki Helsinki Finland FIN-00014 em, FIN-00014 Helsinki, Finland
Titolo Testata:
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
fascicolo: 18, volume: 121, anno: 1999,
pagine: 4348 - 4355
SICI:
0002-7863(19990512)121:18<4348:COSFWH>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
ISOTACTIC PROPENE POLYMERIZATION; ANSA-METALLOCENE DERIVATIVES; PROPYLENE POLYMERIZATION; ELASTOMERIC POLY(PROPYLENE); 2-STATE PROPAGATION; CRYSTAL-STRUCTURE; CHIRAL EPOXIDES; GROWING CHAIN; POLYPROPYLENE; COMPLEXES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Physical, Chemical & Earth Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Rieger, B Univ Ulm, Dept Mat & Catalysis, D-89069 Ulm, Germany Univ Ulm Ulm Germany D-89069 & Catalysis, D-89069 Ulm, Germany
Citazione:
U. Dietrich et al., "Control of stereoerror formation with high-activity "dual-side" zirconocene catalysts: A novel strategy to design the properties of thermoplastic elastic polypropenes", J AM CHEM S, 121(18), 1999, pp. 4348-4355

Abstract

The new C-1-symmetric complexes rac-[1-(9-eta(5)-fluorenyl)-2-(3-methylbenz[e]-1-eta(5)-indenyl)ethane]zirconium dichloride (14a), rac-[1-(9-eta(5)-fluorenyl)-2-(4,5-cyclohexa-2-methyl-1-eta(5)-indenyl)ethane]zirconium dichloride (14b), and rac-[1-(9-eta(5)-fluorenyl)-2-(5,6-cyclopenta-2-methyl-1-eta(5)-indenyl)ethane]zirconium dichloride (15) were prepared in up to 93% yield. These compounds, activated with methyl aluminoxane, exhibit high active propene polymerization rates which remain constant over hours, even at elevated polymerization temperatures of 50 and 70 degrees C. The two different coordination sites of these "dual-side" catalysts lead to isotactic polypropenes with variable amounts of stereoerrors, depending on the monomer concentration, The 2-methyl substituent of the indenyl ligands results, at the same time, in significantly increased molecular weights of the polymer products (up to 2.3 x 10(5) g mol(-1)), the bulk properties of which can be adjusted from flexible, semicrystalline thermoplastic to excellent thermoplastic elastic.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 13:36:57