Elastomeric Poly(propylene): Influence of Catalyst Structure and Polymerization Conditions on Polymer Structure and Properties

Gauthier, William J.; Corrigan, John F.; Taylor, Nicholas J.; Collins, Scott

doi:10.1021/ma00115a004

Cited by 161 publications

(164 citation statements)

References 3 publications

(3 reference statements)

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“…This may relate to the fact that the coordinating ability of the B(C 6 F 5 ) 4 anion is larger than the MAO derived anion 18) . Furthermore, Collins et al 19) showed that this type of catalyst (Me 2 C(Cp)(Ind)ZrCl 2 /MAO) could synthesize elastomeric poly(propylene) with narrow molecular weight distribution, indicating that multi-active sites were also influenced by the kind of monomer.…”

Section: A)mentioning

confidence: 99%

Ethylene/1-hexene copolymerization with Ph2C(Cp)(Flu)ZrCl2 derivatives: correlation between ligand structure and copolymerization behavior at high temperature

Yano¹,

Hasegawa

Kaneko

et al. 1999

Macromol. Chem. Phys.

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SUMMARY: Ethylene homo-and copolymerization with 1-hexene were performed in the presence of diphenylmethylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride (Ph 2 C(Cp)(Flu)ZrCl 2 ) derivatives activated with dimethylanilinium tetrakis(pentafluorophenyl)borate (Me 2 PhNH N B(C 6 F 5 ) 4 )/triisobutylaluminium (iBu 3 Al) or methylaluminoxane (MAO) to study the role of the substituent on activity, comonomer incorporation and molecular weight. C 1 symmetric metallocenes which have several substituents in b-position of the cyclopentadienyl ligand produce lower molecular weight copolymers than the Ph 2 C(Cp)(Flu)ZrCl 2 catalyst at 200 8C, whereas the copolymerization reactivity is significantly influenced by the volume of the substituent: the trimethylsilyl substituted derivative produces ethylene/1-hexene copolymers with a broad chemical composition distribution. Polyethylene obtained with the diphenylmethylidene(cyclopentadienyl)(indenyl)zirconium dichloride (Ph 2 C(Cp)(Ind)ZrCl 2 ) based catalyst is branched, and the molecular weight distribution and the chemical composition distribution are significantly affected by the cocatalyst. C s symmetric metallocenes which have alkyl substituents in 2,7 position of the fluorenyl ligand produce higher molecular weight copolymers than the Ph 2 C(Cp)(Flu)ZrCl 2 catalyst with equal copolymerization reactivity.

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Section: A)mentioning

confidence: 99%

Ethylene/1-hexene copolymerization with Ph2C(Cp)(Flu)ZrCl2 derivatives: correlation between ligand structure and copolymerization behavior at high temperature

Yano¹,

Hasegawa

Kaneko

et al. 1999

Macromol. Chem. Phys.

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“…Zirconocenes obviously showed higher catalytic activity than hafnocenes (1 > 2, 3 > 4, 5 > 6), in agreement with other reports. 7,27,28 The catalytic activities of complexes 1-9 increased with polymerization temperature rising from 60 to 80…”

Section: Synthesis Of Complexesmentioning

confidence: 99%

Ethylene and propylene polymerization by the new substituted bridged (cyclopentadienyl)(fluorenyl) zirconocenes

Yang

Zhang

Huang

2005

Applied Organom Chemis

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Eight Cs-symmetric complexes, R 1 R 2 C(Cp)(Flu)MCl 2 [R 1 = R 2 = CH 3 CH 2 CH 2 , M = Zr (1), Hf (2); R 1 = R 2 = p-CH 3 OC 6 H 4 , M = Zr (3), Hf (4); R 1 = p-t BuC 6 H 4 , R 2 = Ph, M = Zr (5), Hf (6); R 1 = R 2 = p-t BuC 6 H 4 , M = Zr (7); R 1 = R 2 = PhCH 2 , M = Zr (8)] have been synthesized and characterized. Zirconocenes all showed the same high catalytic activities in ethylene polymerization as complex Ph 2 C(Cp)(Flu)ZrCl 2 (9). However, in the propylene polymerization, the catalytic activities decreased in the order 5 ≈ 9 > 7 > 8. Introduction of t Bu decreased the activities, probably due to the bulk steric hindrance. The polypropylene produced by 5 and 7 with t Bu substituent showed a higher molecular weight (Mη) than that produced by 9. The 13 C NMR spectrum revealed the polymers from 7 and 8 to have shorter average syndiotactic block length than polymer produced by 9. It was noted that [mm] stereodefect of polypropylene by 8 could not be observed from 13 C NMR, which showed that the benzyl on bridge carbon 8 prevented chain epimerization and enatiofacial misinsertion in polymerization.

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“…15 After that, Matthew et al reported that 2-substituted indenyl zirconocenes were active for ethylene homopolymerization. 16 However, little information was available on the ethylene or ethylene/1-hexene copolymerization with the bridged (cyclopentadienyl) (indenyl) metallocenes.…”

Section: Introductionmentioning

confidence: 99%

α‐olefin homopolymerization and ethylene/1‐hexene copolymerization catalysed by novel ansa‐group IV complexes/MAO system

Yang

Zhang

Huang

2007

Applied Organom Chemis

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The catalytic properties of a set of ansa-complexes (R-Ph) 2 C(Cp)(Ind)MCl 2 [R = t Bu, M = Ti (3), Zr (4) or Hf (5); R = MeO, M = Zr (6), Hf (7)] in α-olefin homopolymerization and ethylene/1-hexene copolymerization were explored in the presence of MAO (methylaluminoxane). Complex 4 with steric bulk t Bu group on phenyl exhibited remarkable catalytic activity for ethylene polymerization. It was 1.6-fold more active than complex 11 [Ph 2 C(Cp)(Ind)ZrCl 2 ] at 11 atm ethylene pressure and was 4.8-fold more active at 1 atm pressure. The introduction of bulk substituent t Bu into phenyl groups not only increased the catalytic activity greatly but also enhanced the content of 1-hexene in ethylene/1-hexene copolymerization. The highest 1-hexene incorporation was 25.4%. In addition, 4 was also active for propylene and 1-hexene homopolymerization, respectively, and low isotactic polypropylene (mmmm = 11.3%) and isotactic polyhexene (mmmm = 31.6%) were obtained.

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Elastomeric Poly(propylene): Influence of Catalyst Structure and Polymerization Conditions on Polymer Structure and Properties

Cited by 161 publications

References 3 publications

Ethylene/1-hexene copolymerization with Ph2C(Cp)(Flu)ZrCl2 derivatives: correlation between ligand structure and copolymerization behavior at high temperature

Ethylene/1-hexene copolymerization with Ph2C(Cp)(Flu)ZrCl2 derivatives: correlation between ligand structure and copolymerization behavior at high temperature

Ethylene and propylene polymerization by the new substituted bridged (cyclopentadienyl)(fluorenyl) zirconocenes

α‐olefin homopolymerization and ethylene/1‐hexene copolymerization catalysed by novel ansa‐group IV complexes/MAO system

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