Effects of Cocatalysts on Propene Polymerization with [t-BuNSiMe2(C5Me4)]TiMe2

Ioku, Atau; Hasan, Tariqul; Shiono, Takeshi; Ikeda, Tomiki

doi:10.1002/1521-3935(20020301)203:4<748::aid-macp748>3.0.co;2-g

Cited by 34 publications

(31 citation statements)

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“…CGC-Ti was also used for comparison. 27 The results are shown in Table 5. The polymerization time was changed in each experiment according to the catalytic activity because the produced polymer interfered with effective stirring.…”

Section: Polymerization Of Propene and Higher 1-alkenementioning

confidence: 99%

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Shiono

2011

Polym J

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This article reviews the living homopolymerization and copolymerization of propene, 1-alkene and norbornene with ansadimethysilylene(fluorenyl)(amido)dimethyltitanium, Me 2 Si(g 3 -C 13 H 8 )(g 1 -N t Bu)TiMe 2 and its derivatives, correlating the effects of cocatalysts, solvents, polymerization conditions and the substituents of the fluorenyl ligand with catalytic features, such as livingness, initiation efficiency, propagation rate, syndiospecificity and copolymerization ability. The synthesis of novel olefin block copolymers and their catalytic synthesis are also introduced using this living system. Polymer Journal (2011) 43, 331-351; doi:10.1038/pj.2011 Keywords: cycloolefin copolymer; living polymerization; norbornene; propene; single-site catalyst; syndiospecific polymerization; 1-alkene A living polymerization system, in which neither chain transfer nor deactivation occurs, affords polymers with predictable molecular weights and narrow molecular weight distributions (MWDs). Living polymerization techniques are utilized for the synthesis of terminally functionalized polymers and block copolymers. Another feature of living polymerization is its simple kinetics. Because neither chain transfer nor deactivation occurs in living polymerization, the number of polymer chains (N) is equal to the number of active centers ([C*]), and the number-average molecular weight (M n ) directly reflects the propagation rate. In living polymerization, the propagation rate can be evaluated from the M n value and the polymerization time. As chain transfer via b-elimination and/or transmetalation with trialkylaluminum as a cocatalyst is inevitable in conventional Ziegler-Natta catalytic systems; homogeneous V(acac) 3 /Et 2 AlCl (where acac is acetylacetonate or its analog) had previously been the only catalytic system that produced syndiotactic-rich living polypropylene (PP) atThe development of metallocene catalysts has enabled us to produce a variety of uniform olefin copolymers and to control the stereoregularity of poly(1-alkene)s. 3,4 The success of metallocene catalysts has stimulated research on transition metal complexes for olefin polymerization, 5-7 so-called single-site catalysts, which has also resulted in various transition metal complexes for the living polymerization of olefins. 8,9 We have also developed a living polymerization system using ansa-dimethysilylene(fluorenyl)(amido)dimethyltitanium, Me 2 Si(Z 3 -C 13 H 8 )(Z 1 -N t Bu)TiMe 2 (1), combined with a suitable cocatalyst. The catalytic system allows not only a syndiospecific living polymerization of propene and a 1-alkene but also a living homopolymerization and copolymerization of norbornene with a 1-alkene. We investigated the effect of cocatalyst, solvent and the ligand of the titanium complex on propene polymerization in terms of the livingness of the system. We also synthesized novel olefin block copolymers with the living system. This article reviews the characteristics of 1-based catalysts for tailor-made polyolefins. SYNTHESIS AND STRUCTURES OF TIT...

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Section: Polymerization Of Propene and Higher 1-alkenementioning

confidence: 99%

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Shiono

2011

Polym J

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“…[13,14] Similar effects of TIBA on propene polymerizations were also reported for some constrained geometry titanium catalysts, [15,16] while for the system Me 2 Si(2-Me-4-PhInd) 2 ZrCl 2 /MAO, partial replacement of MAO with TIBA prolonged the catalyst activity. [17] The addition of TIBA increases the activity of several homogeneous zirconocene/MAO systems in the copolymerization of propylene with hex-1-ene.…”

Section: Introductionmentioning

confidence: 99%

Activation of rac‐Me₂Si(ind)₂ZrCl₂ by Methylalumoxane Modified by Aluminum Alkyls: An EPR Spin‐Probe, ¹H NMR, and Polymerization Study

Bryliakov

Semikolenova

Panchenko

et al. 2006

Macro Chemistry & Physics

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Summary: Solutions containing mixtures of methylalumoxane (MAO) and iBu3Al give rise to 1H NMR signals indicative of the presence of the mixed alkyl aluminum dimers iBu2Al(µ‐Me)2AliBu2 and of mixed clusters of the type (AlMe(1 + 2x − y)iBuyO(1 − x))n. These mixed clusters, as well as related species present in solutions containing either MAO–Et3Al or commercially available modified MAO (MMAO), appear to have stronger Lewis acidic sites and greater hydrodynamic radii than comparable clusters present in solutions of MAO alone, as judged from EPR signals observed in these solutions upon addition of TEMPO. When (SBI)ZrCl2 (SBI = rac‐Me2Si(ind)2) is reacted with one of these mixed activator reagents, the mixed heterobinuclear cation [(SBI)Zr(µ‐Me)2AlMeiBu]+ appears to be formed, together with its methyl counterpart [(SBI)Zr(µ‐Me)2AlMe2]+, which is normally predominant in the (SBI)ZrCl2/MAO system at [Al]MAO/[Zr] ratios above 100. In the presence of iBu3Al, the formation of heterobinuclear cations is suppressed in favor of ion pairs containing the cation [(SBI)ZrMe]+ in contact with a (MAO–TIBA)‐derived counter anion. The greater reactivity of these contact‐ion pairs, as compared to the normally prevalent AlMe3 adducts, as well as an increased Lewis acidity of MMAO, and the ensuing decreased coordination ability of the [Me‐(MAO–TIBA)]− counter ion as compared to [Me‐MAO]−, are likely to contribute to the positive effects of TIBA additions on the co‐catalytic activity of MAO. magnified image

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“…[5] In this case, the aluminium species were all 4-coordinated Al species. Several groups have reported that cocatalysts influence not only the productivity of polymers but also the structure of the polymers obtained, such as molecular weight, [6][7][8][9] stereoregularity [9][10][11][12][13][14] or regioregularity. [14,15] It is known that MAO solution contains ''free'' trialkylaluminium which acts as a chain transfer agent and/ or lowers the productivity.…”

Section: Introductionmentioning

confidence: 99%

“…Several groups have reported that cocatalysts influence not only the productivity of polymers but also the structure of the polymers obtained, such as molecular weight, [6][7][8][9] stereoregularity [9][10][11][12][13][14] or regioregularity. [14,15] It is known that MAO solution contains ''free'' trialkylaluminium which acts as a chain transfer agent and/ or lowers the productivity. [7,[16][17][18][19][20] Shiono and co-workers studied the effect of reduction or addition of ''free'' trialkylaluminium.…”

Section: Introductionmentioning

confidence: 99%

“…[14,15] It is known that MAO solution contains ''free'' trialkylaluminium which acts as a chain transfer agent and/ or lowers the productivity. [7,[16][17][18][19][20] Shiono and co-workers studied the effect of reduction or addition of ''free'' trialkylaluminium. [7,[17][18][19][20] Busico et al also reported a method for trapping ''free'' trimethylaluminium using 2,6-t Bu 2 PhOH, in order to improve the productivity of single-site catalysts.…”

Section: Introductionmentioning

confidence: 99%

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Enhancement of Productivity, Molecular Weight and Stereoregularity of 1‐Butene Polymerization by MAO Modification

Fujita

Seki

Miyatake

2004

Macro Chemistry & Physics

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Summary: The modification of MMAO using water and pentafluorophenol enhances the productivity, molecular weight, regioregularity and stereoregularity of the polymer obtained from the polymerization of 1‐butene with TBPTiCl2. The structural changes in water modified‐MMAO (WM‐MMAO) and water/pentafluorophenol‐modified‐MMAO (W/PM‐MMAO) were revealed by 27Al MAS NMR. Although only 4‐ and 6‐coordinated aluminium species existed in the MMAO, a new peak derived from a 5‐coordinated Al species appeared when the water or water/phenol modification was carried out. This result suggests that a 5‐coordinated aluminium species of WM‐ or W/PM‐MMAO might significantly influence the behavior of the single‐site catalyst.Structure of the here used catalyst.imageStructure of the here used catalyst.

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Effects of Cocatalysts on Propene Polymerization with [t-BuNSiMe2(C5Me4)]TiMe2

Cited by 34 publications

References 18 publications

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Activation of rac‐Me₂Si(ind)₂ZrCl₂ by Methylalumoxane Modified by Aluminum Alkyls: An EPR Spin‐Probe, ¹H NMR, and Polymerization Study

Enhancement of Productivity, Molecular Weight and Stereoregularity of 1‐Butene Polymerization by MAO Modification

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Effects of Cocatalysts on Propene Polymerization with [t-BuNSiMe2(C5Me4)]TiMe2

Cited by 34 publications

References 18 publications

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Living polymerization of olefins with ansa-dimethylsilylene(fluorenyl)(amido)dimethyltitanium-based catalysts

Activation of rac‐Me2Si(ind)2ZrCl2 by Methylalumoxane Modified by Aluminum Alkyls: An EPR Spin‐Probe, 1H NMR, and Polymerization Study

Enhancement of Productivity, Molecular Weight and Stereoregularity of 1‐Butene Polymerization by MAO Modification

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Activation of rac‐Me₂Si(ind)₂ZrCl₂ by Methylalumoxane Modified by Aluminum Alkyls: An EPR Spin‐Probe, ¹H NMR, and Polymerization Study