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Titolo:
Ethylene/alpha-olefin copolymerization by various nonbridged (cyclopentadienyl)(aryloxy)titanium(IV) complexes - MAO catalyst system
Autore:
Nomura, K; Oya, K; Imanishi, Y;
Indirizzi:
Nara Inst Sci & Technol, Grad Sch Mat Sci, Nara 6300101, Japan Nara Inst Sci & Technol Nara Japan 6300101 Mat Sci, Nara 6300101, Japan
Titolo Testata:
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
fascicolo: 1-2, volume: 174, anno: 2001,
pagine: 127 - 140
SICI:
1381-1169(20011001)174:1-2<127:ECBVN(>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
R = H; POLYMERIZATION CATALYSTS; ETHYLENE/1-HEXENE COPOLYMERIZATION; ALTERNATING COPOLYMERIZATION; DICHLORIDE-METHYLALUMINOXANE; ZIRCONIUM COMPLEXES; ARYLOXY COMPLEXES; AMIDO CATALYSTS; CYCLOPENTADIENYL; GROUP-4;
Keywords:
olefin polymerization; titanium(IV); ethylene;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Nomura, K Nara Inst Sci & Technol, Grad Sch Mat Sci, 8916-5 Takayama, Nara6300101, Japan Nara Inst Sci & Technol 8916-5 Takayama Nara Japan 6300101apan
Citazione:
K. Nomura et al., "Ethylene/alpha-olefin copolymerization by various nonbridged (cyclopentadienyl)(aryloxy)titanium(IV) complexes - MAO catalyst system", J MOL CAT A, 174(1-2), 2001, pp. 127-140

Abstract

Effect of ligand in copolymerization of ethylene with 1-hexene by (cyclopentadienyl)(aryloxy)titanium(IV) complexes of the type, Cp'TiCl2(OAr) [OAr =O-2,6-(Pr2C6H3)-Pr-i and Cp' = C5Me5 (1), 1,3-(Bu2C5H3)-Bu-t (2), (Bu2C5H4)-Bu-t (3), 1,3-Me2C5H3 (5), Cp (6); OAr = O-2,6-Me2C6H3 and Cp' = C5Me5 (7),1,3-(Bu2C5H3)-Bu-t (8)], has been explored in the presence of MAO, and [Me2Si(C5Me4)((NBu)-Bu-t)]TiCl2 (4) was chosen as the reference. It was revealed that 1 exhibited the highest catalytic activity, and the resultant poly(ethylene-co-1-hexene)s possessed relatively high molecular weights with narrow molecular weight distributions (M-w = 29.5 x 10(4) to 34.5 x 10(4), M-w/M-n = 1.74-1.88), and contained 1-hexene in relatively high extents (36.6-43.5 mol%). Effect of both cyclopentadienyl and aryloxy groups plays an essential key role in the copolymerization not only to exhibit high catalyticactivity but also to afford relatively high molecular weight copolymer with narrow polydispersity. It also turned out that a-olefin incorporation into the copolymer is highly affected by the substituents on the cyclopentadienyl group. The monomer reactivity ratios were not affected by both the polymerization temperature and Al/Ti molar ratios, but the monomer sequence distributions and the monomer reactivity ratios depended upon cyclopentadienyl fragment used. In spiteof the rather wide bond angle of Cp-Ti-O (ca. 120.5 degrees) in 1-3 than that of Cp-Ti-N in 4 (107.6 degrees), a high level of 1-hexene incorporationand smaller r(E)r(H), value by 1-3 than those by 4 were attained, which would be due to the flexible internal rotation of both cyclopentadienyl and aryloxy groups. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 09:12:21