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1

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Polymerization of olefins with a novel dinuclear ansa-zirconocene catalyst having a biphenyl bridge (1998)

Ban, Hoang The ; Uozumi, Toshiya ; Soga, Kazuo

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2269-2274

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ISSN: 0887-624X

Keywords: dinuclear ansa-zirconocene catalyst ; diastereomers ; biphenyl and phenyl ligands ; polymerization of ethene and propene ; copolymerization of ethene and 1-octene ; thermal stability of active species ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Both the rac- and meso-dinuclear ansa-zirconocene catalysts (μ-C12H8{[SiPh(Ind)2]ZrCl2}2) were prepared by a coupling reaction between 2 equiv of diindenylphenylchlorosilane (rac- and meso-isomers) and 1 equiv of p-dilithiobiphenyl in diethyl ether at -80°C, followed by a successive reaction with ZrCl4 · 2THF in THF at -78°C. Polymerizations of ethene and propene were conducted in a 1 dm3 high-pressure glass reactor equipped with a mechanical stirrer at 60, 80, 100, 120, and 150°C using methylalumoxane (MAO) as cocatalyst and toluene or decahydronaphthalene as the solvent. Copolymerization of ethene and 1-octene was also checked in brief. For ethene polymerization, the meso-catalyst was found to be more active, which displayed an extremely high activity to give linear polyethene with a high molecular weight and a narrow molar mass distribution (MMD). The apparent activity increased monotonously with rising polymerization temperature from 60°C up to 150°C, indicating that the active species are stable even at a high temperature. On the other hand, both the rac- and meso-catalysts showed very poor activities for propene polymerization. However, copolymerization of ethene and 1-octene proceeded at a high speed. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2269-2274, 1998

Additional Material: 4 Ill.

Type of Medium: Electronic Resource

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2

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Syntheses of poly(siloxane)-supported zirconocene catalysts and application to olefin polymerizations (1998)

Arai, Takashi ; Ban, Hoang The ; Uozumi, Toshiya ; [et al.]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 421-428

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ISSN: 0887-624X

Keywords: poly(siloxane)-supported zirconocene catalysts ; polymerizations of ethene and propene ; copolymerization of ethene with 1-octene ; Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Notes: Poly(siloxane)s with bisindenyl, bisfluorenyl, bis(1,2,3,4-tetramethylcyclopentadienyl), bis(2,4,7-trimethylindenyl) and monoindenylmethyl side groups were synthesized by condensation of the corresponding dichlorosilanes and water. For reference, diphenylsilanediol or hydroquinone was also employed in place of water. A series of poly(siloxane)-supported zirconocene catalysts were then prepared from these precursors and applied to ethene and propene polymerizations as well as to the copolymerization of ethene with 1-octene in the presence of methylalumoxane. The polymerization activity of the new supported metallocenes depends drastically upon the substituents in the siloxane backbone. The zirconocene catalysts supported on poly(bisindenylsiloxane) and poly(bisfluorenylsiloxane) give the highest activities for ethene and propene polymerizations, respectively. The weight-average molecular weights of the polymers are also markedly dependent upon the substituents. On the other hand, the molecular mass distributions (MMD) are generally not so sharp, suggesting that the active species formed in these supported catalysts are not uniform. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 421-428, 1998

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Syntheses of polysiloxane-supported zirconocene catalysts and application to ethene polymerization (1997)

Arai, Takashi ; Ban, Hoang The ; Uozumi, Toshiya ; [et al.]

Weinheim : Wiley-Blackwell

Macromolecular Chemistry and Physics 198 (1997), S. 229-237

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ISSN: 1022-1352

Keywords: Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Physics

Notes: Polysiloxanes with bisindenyl, bisfluorenyl, and bis(1,2,3,4-tetramethyl)cyclopentadienyl side groups were synthesized by condensation of the corresponding dichlorosilane compounds and water to obtain supported ziroconocene catalysts. The polymerization of ethene was conducted over these catalysts combined with methylalumoxane. The polymerization activity depends markedly upon the substituents and decreases in the order: bisindenyl ≫ bisfluorenyl ≫ bis(1,2,3,4-tetramethylcyclopentadienyl). All the supported catalysts give linear polyethene with fairly high molecular weights. The catalyst with bisindenyl groups was found to be composed of a toluene-soluble and a toluene-insoluble fraction. The polymerization profile (activity versus time curve) was analyzed with the toluene-soluble and -insoluble fraction as well as the corresponding homogeneous system. The homogeneous system, which exerts the highest activity in the initial phase, was completely deactivated after several hours whereas the activity of the supported catalyst, especially of the toluene-insoluble fraction, was unchanged during 12 h even at 70°C. Polysiloxanes with different content of bisindenyl groups were also synthesized via the co-condensation with dimethyldichlorosilane and applied as the carrier. However, the activity per Zr atom decreases remarkably with an increase in dimethylsilane units.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/macp.1997.021980201

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4

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Propene polymerization with zirconocene catalysts supported on siloxane copolymers (1997)

Soga, Kazuo ; Ban, Hoang The ; Arai, Takashi ; [et al.]

Weinheim : Wiley-Blackwell

Macromolecular Chemistry and Physics 198 (1997), S. 2779-2787

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ISSN: 1022-1352

Keywords: Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Physics

Notes: A supported version of zirconocene catalysts on siloxane copolymers having 1,2,3,4-tetramethylcyclopentadienyl (Cp″)-fluorenyl (Flu) (I) or cyclopentadienyl (Cp)-fluorenyl (II) groups as substituents was prepared and applied to propene polymerization using methylalumoxane (MAO) or [Ph3C][B(C6F5)4] as cocatalyst. Catalyst (I), which was soluble in toluene, exhibited very low activity, whereas catalyst (II), which was composed of a toluene soluble (Cat-A) and an insoluble fraction (Cat-B), displayed a fairly high activity. Both catalysts (A and B) give a mixture of syndiotactic, atactic and a small quantity of isotactic polypropene, with a fraction of syndiotactic pentads ranging from about 50-75%. In contrast, the corresponding non-supported catalyst gives almost completely atactic polypropene.

Additional Material: 9 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/macp.1997.021980910

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5

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Ethene polymerization with a poly(styrene-co-divinylbenzene) beads supported rac-Ph2Si(Ind)2ZrCl2 catalyst (1998)

Hong, Sung Chul ; Ban, Hoang The ; Kishi, Naoya ; [et al.]

Weinheim : Wiley-Blackwell

Macromolecular Chemistry and Physics 199 (1998), S. 1393-1397

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ISSN: 1022-1352

Keywords: Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Physics

Notes: Poly(styrene-co-divinylbenzene) beads supported rac-Ph2Si(Ind)2ZrCl2 was prepared and tested as a catalyst for ethene polymerization using methylaluminoxane (MAO) as a cocatalyst. At a polymerization temperature below 100°C, the catalyst showed pretty high activity to give polyethene beads replicating the shape of the carrier. With increasing polymerization temperature up to 150°C, the catalyst activity increased drastically but the spherical shape of polyethene disappeared due to the melting. From the plots of apparent activity against polymerization temperature, it was suggested that the polymerization below 100°C is more or less controlled by monomer diffusion through the crystalline polyethene films.

Additional Material: 3 Ill.

Type of Medium: Electronic Resource

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