Advertisement

Ethylene-Propene Copolymerization with C1-symmetric ansa-Fluorenyl-zirconocene Catalysts: Effects of Catalyst Structure and Comonomer on Molar Mass

  • Simona Losio
  • Laura Boggioni
  • Massimiliano Cornelio
  • Abbas Razavi
  • Incoronata TrittoEmail author
Article
  • 4 Downloads

Abstract

Ethylene-propene copolymers have been synthesized by three C1-symmetric metallocene molecules (1, 2, and 3), having tert-butyl substituents on the Cp moiety, on the fluorenyl moiety, or on both moieties, and methylaluminoxane (MAO) at different polymerization temperatures and monomer concentrations. Copolymers were investigated by 13C-NMR, 1H-NMR, and SEC analyses. A relationship was found between [EEE]/[E] ratios and copolymer molar masses in each series: the higher the [EEE]/[E] ratio, the lower the copolymer molar mass. At parity of [EEE]/[E] ratio, copolymer molar mass follows the order 1 >> 3 > 2. Chain end group analysis reveals that copolymers mainly terminate when propene is the last inserted unit, confirming that it is the greater facility of Mt-P-E-poly(E-co-P) to terminate that influences the copolymer molar mass. Among the catalysts considered, catalyst 1, which gives syndiospecific polypropene, gives greater activities, comonomer incorporation, and molar masses. Catalyst 3, which gives isospecific polypropene, in copolymerization performs better than 2, having the same bridge, with respect to activities, ethylene content, and molar masses. The good performance of this catalyst arises from the not necessity of polymer chain to back skip when ethylene is the last inserted unit.

Keywords

Ethylene-propene Metallocene catalysts Copolymers Microstructure Molar masses 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgments

This work was financially supported by Total. We thank G. Zannoni and D. Piovani (ISMAC) for their valuable cooperation in NMR and SEC analysis.

References

  1. 1.
    Sturzel, M.; Mihan, S.; Mulhaupt, R. From multisite polymerization catalysis to sustainable materials and all-polyolefin composites. Chem. Rev.2016, 116, 1398–1433.PubMedCrossRefGoogle Scholar
  2. 2.
    Busico, V. Metal-catalysed olefin polymerisation into the new millennium: A perspective outlook. Dalton Trans.2009, 8794–8802.Google Scholar
  3. 3.
    Brintzinger, H. H.; Fischer, D.; Mülhaupt, R.; Rieger, B.; Waymouth, R. Stereospecific olefin polymerization with chiral metallocene catalysts. Angew. Chem. Int. Ed.1995, 34, 1143–1170.CrossRefGoogle Scholar
  4. 4.
    Resconi, L.; Cavallo, L.; Fait, A.; Piemontesi, F. Selectivity in propene polymerization with metallocene catalysts. Chem. Rev. 2000, 100, 1253–1345.PubMedCrossRefGoogle Scholar
  5. 5.
    Razavi, A.; Thewalt, U. Site selective ligand modification and tactic variation in polypropylene chains produced with metallocene catalysts. Coord. Chem. Rev.2006, 250, 155–169.CrossRefGoogle Scholar
  6. 6.
    Kaminsky, W.; Sperber, O.; Werner, R. Pentalene substituted metallocene complexes for olefin polymerization. Coord. Chem. Rev.2006, 250, 110–117.CrossRefGoogle Scholar
  7. 7.
    Spalech, W.; Kuber, F.; Winter, A.; Rohrmann, J.; Bachmann, B.; Antberg, M.; Dolle, V.; Paulus, E. F. The influence of aromatic substituents on the polymerization behavior of bridged zirconocene catalysts. Organometallics1994, 13, 954–963.CrossRefGoogle Scholar
  8. 8.
    Spaleck, W.; Antberg, M.; Rohrmann, J.; Winter, A.; Bachmann, B.; Krprof, B.; Behm, J.; Herrmann, A. W. High-molecular-weight polypropylene through specifically designed zirconocene catalysts. Angew. Chem.1992, 31, 1347–1350.CrossRefGoogle Scholar
  9. 9.
    Stehling, U.; Diebold, J.; Kirsten, R.; Roll, W.; Brintzinger, H. H.; Jungling, S.; Mulhaupt, R.; Langahuster, F. ansa-Zirconocene polymerization catalysts with annelated ring ligands-effects on catalytic activity and polymer-chain lenght. Organometallics1994, 13, 964–970.CrossRefGoogle Scholar
  10. 10.
    Kirillov, E.; Roisnel, T.; Razavi, A.; Carpentier, J. F. Group 4 post-metallocene complexes incorporating tridentate silyl-substituted bis(naphthoxy)pyridine and bis(naphthoxy)thiophene ligands: Probing systems for “oscillating” olefin polymerization catalysis. Organometallics2009, 28, 5036–5051.CrossRefGoogle Scholar
  11. 11.
    Fan, W.; Waymouth, R. M. Sequence and stereoselectivity of the C 1-symmetric metallocene Me2Si(1-(4,7-Me2Ind))(9-Flu)ZrCl2. Macromolecules2003, 36, 3010–3014.CrossRefGoogle Scholar
  12. 12.
    Ewen, J. A.; Jones, R. L.; Razavi, A.; Ferrara, J. D. Syndiospecific propylene polymerizations with group-4 metallocenes. J. Am. Chem. Soc.1988, 110, 6255–6256.PubMedCrossRefGoogle Scholar
  13. 13.
    Razavi, A.; Atwood, J. L. Preparation and crystal-structures of the complexes (η 5-C5H3Me-CMe2-η 5-C13H8)MCL2 (M = Zr or Hf)—Mechanistic aspects of the catalytic formation of a syndiotactic-isotactic stereoblock-type polypropylene. J. Organomet. Chem.1995, 497, 105–111.CrossRefGoogle Scholar
  14. 14.
    Razavi, A.; Atwood, J. L. Preparation and crystal-structures of the complexes (η 5-C5H4CPH2-η 5-C13H8)MCL2 (M = Zr, Hf) and the catalytic formation of high molecular weight-high tacticity-syndiotactic polypropylene. J. Organomet. Chem.1996, 520, 115–120.CrossRefGoogle Scholar
  15. 15.
    Ewen, J. A.; Elder, M. J.; Jones, R. L.; Curtis, S.; Cheng, H. N. In Catalytic olefin polymerization, studies in surface science and catalysis. Eds. Keii, T. and Soga, K. Elsewier, New York, 1990, p. 439.Google Scholar
  16. 16.
    Razavi, A.; Peters, L.; Nafpliotis, L.; Vereecke, D.; Den Dauw, K. The geometry of the site and its relevance for chain migration and stereospecificity. Macromol. Symp.1995, 89, 345–367.CrossRefGoogle Scholar
  17. 17.
    Miller, S. A.; Bercaw, J. E. Mechanism of isotactic polypropylene formation with C-1-symmetric metallocene catalysts. Organometallics2006, 25, 3576–3592.CrossRefGoogle Scholar
  18. 18.
    Boggioni, L.; Cornelio, M.; Losio, S.; Razavi, A.; Tritto I. Propene polymerization with C 1-symmetric fluorenyl-metallocene catalysts. Polymers2017, 9, 181–199.CrossRefGoogle Scholar
  19. 19.
    Spaleck, W.; Antberg, M.; Dolle, V.; Klein, R.; Rohrmann, J.; Winter, A. Stereorigid metallocenes—Correlations between structure and behavior in homopolymerizations of propylene. J. Chem.1990, 13, 499–503.Google Scholar
  20. 20.
    Reybuck, S. E.; Meyer, A.; Waymouth, R. M. Copolymerization behavior of unbridged indenyl metallocenes: Substituent effects on the degree of comonomer incorporation. Macromolecules2002, 35, 637–643.CrossRefGoogle Scholar
  21. 21.
    Tynys, A.; Saarinen, T.; Hakala, K.; Helaja, T.; Vanne, T.; Lehmus, P.; Löfgren, B. Ethylene-propylene copolymerisations: Effect of metallocene structure on termination reactions and polymer microstructure. Macromol. Chem. Phys.2005, 206, 1043–1056.CrossRefGoogle Scholar
  22. 22.
    Yano, A.; Hasegawa, S.; Kaneko, T.; Sone, M.; Akimoto, A. Ethylene/1-hexene copolymerization with Ph2C(Cp)(Flu)ZrCl2 derivatives: Correlation between ligand structure and copolymerization behavior at high temperature. Macromol. Chem. Phys.1999, 200, 1542–1553.CrossRefGoogle Scholar
  23. 23.
    Suhm, J.; Schneider, M. J.; Mulhaupt, R. Influence of metallocene structures on ethene copolymerization with 1-butene and 1-octene. J. Mol. Catal. A: Chem.1998, 128, 215–217.CrossRefGoogle Scholar
  24. 24.
    Schneider, M. J.; Suhm, J.; Mulhaupt, R.; Prosenc, M.; Brintzinger, H. Influence of indenyl ligand substitution pattern on metallocene-catalyzed ethene copolymerization with 1-octene. Macromolecules1997, 30, 3164–3168.CrossRefGoogle Scholar
  25. 25.
    Seraidaris, T.; Löfgren, B.; Seppälä, J. V.; Kaminsky, W. Copolymerization of propene with low amounts of ethene in propene bulk phase. Polymer2006, 47, 107–112.CrossRefGoogle Scholar
  26. 26.
    Wang, D.; Tomasi, S.; Razavi, A.; Ziegler, T. Why do C1-symmetric ansa-zirconocene catalysts produce lower molecular weight polymers for ethylene/propylene copolymerization than for ethylene/propylene homopolymerization? Organometallics2008, 27, 2861–2867.CrossRefGoogle Scholar
  27. 27.
    Busico, V.; Cipullo, R.; Talarico, G.; Segre, A. L.; Caporaso, L. High-field 13C NMR characterization of ethene-1-13C/propene copolymers prepared with Cs-symmetric ansa-metallocene catalysts: A deeper insight into the regio- and stereoselectivity of syndiotactic propene polymerization. Macromolecules1998, 31, 8720–8724.CrossRefGoogle Scholar
  28. 28.
    Tritto, I.; Fan, Z, Q.; Locatelli, P.; Sacchi, M. C.; Camurati; Galimberti, M. 13C NMR-studies of ethylene-propylene copolymers prepared with homogeneous metallocene-based Ziegler-Natta catalysts. Macromolecules1995, 28, 3342–3350.CrossRefGoogle Scholar
  29. 29.
    Losio, S.; Boccia, A. C.; Boggioni, L.; Sacchi, M. C.; Ferro, D. R. Ethene/4-methyl-1-pentene copolymers by metallocene-based catalysts: Exhaustive microstructural characterization by 13C NMR spectroscopy. Macromolecules2009, 42, 6964–6971.CrossRefGoogle Scholar
  30. 30.
    Losio, S.; Forlini, F.; Boccia, A. C.; Sacchi, M. C. Propene/4-methyl-1-pentene copolymers by metallocene-based catalysts: First insight into 13C-NMR assignment. Macromolecules2011, 44, 3276–3286.CrossRefGoogle Scholar
  31. 31.
    Tritto, I.; Boggioni, L.; Zampa, C.; Ferro, D. R. Ethylene-norbornene copolymers by Cs-symmetric metallocenes: Determination of the copolymerization parameters and mechanistic considerations on the basis of tetrad analysis. Macromolecules2005, 38, 9910–9919.CrossRefGoogle Scholar
  32. 32.
    Boggioni, L.; Ravasio, A.; Boccia, A. C.; Ferro, D. R.; Tritto, I. Propene-norbornene copolymers toward a description of microstructure at triad level based on assignments of 13C-NMR spectra. Macromolecules2010, 43, 4543–4556.CrossRefGoogle Scholar
  33. 33.
    Harakawa, H.; Patamma, S.; Boccia, A. C.; Boggioni, L.; Ferro, D. R.; Losio, S.; Nomura, K.; Tritto, I. Ethylene copolymerization with 4-methylcyclohexene or 1-methylcyclopentene by half-titanocene catalysts: Effect of ligands and microstructural analysis of the copolymers. Macromolecules2018, 51, 853–863.CrossRefGoogle Scholar
  34. 34.
    Carman, C. J.; Wilkes, C. E. Monomer sequence distribution in ethylene propylene elastomers I. Measurement by carbon-13 nuclear magnetic resonance spectroscopy. Rubber Chem. Technol.1971, 44, 781–804.CrossRefGoogle Scholar
  35. 35.
    Dorman, D. E.; Otocka, E. P.; Bovey, F. A. Carbon-13 observations of the nature of the short-chain branches in low-density polyethylene. Macromolecules1972, 5, 574–577.CrossRefGoogle Scholar
  36. 36.
    Randall, J. C. A review of high resolution liquid 13carbon nuclear magnetic resonance characterizations of ethylene-based polymers. J. Macromol. Sci., Rev. Macromol. Chem. Phys.1989, C29(2&3), 201.CrossRefGoogle Scholar
  37. 37.
    Kakugo, M.; Naito, Y.; Mizunuma, K.; Miyatake, T. Carbon-13 NMR determination of monomer sequence distribution in ethylene-propylene copolymers prepared with ô-titanium trichloridediethylaluminum chloride. Macromolecules1982, 15, 1150–1152.CrossRefGoogle Scholar
  38. 38.
    Ray, G. J.; Johnson, P. E.; Knox, J. R. Carbon-13 nuclear magnetic resonance determination of monomer composition and sequence distributions in ethylene-propylene copolymers prepared with a stereoregular catalyst system. Macromolecules1977, 10, 773–778.CrossRefGoogle Scholar
  39. 39.
    Galimberti, M.; Piemontesi, F.; Mascellani, N.; Camurati, I.; Fusco, O.; Destro, M. Metallocenes for ethene/propene copolymerizations with high product of reactivity ratios. Macromolecules1999, 32, 7968–7976.CrossRefGoogle Scholar
  40. 40.
    Lehmus, P.; Kokko, E.; Leino, R.; Luttikhedde, H. J. G.; Rieger, B.; Seppala, J. V. Chain end isomerization as a side reaction in metallocene-catalyzed ethylene and propylene polymerizations. Macromolecules2000, 33, 8534–8540.CrossRefGoogle Scholar
  41. 41.
    Lehmus, P.; Kokko, E.; Ha1rkki, O.; Leino, R.; Luttikhedde, H. J. G.; Nasman, J. H.; Seppala, J. V. Homo- and copolymerization of ethylene and α-olefins over 1- and 2-siloxy-substituted ethylenebis(indenyl)zirconium and ethylenebis-(tetrahydroindenyl)-zirconium dichlorides. Macromolecules1999, 32, 3547–3552.CrossRefGoogle Scholar
  42. 42.
    Tritto, I.; Boggioni, L.; Ferro, D. R. Metallocene catalyzed ethene- and propene co-norbornene polymerization: Mechanisms from a detailed microstructural analysis. Coord. Chem. Rev.2006, 250, 212–241.CrossRefGoogle Scholar
  43. 43.
    Resconi, L.; Camurati, I.; Sudmeijer, O. Chain transfer reactions in propylene polymerization with zirconocene catalysts. Topics in Catalysis1999, 7, 145–163.CrossRefGoogle Scholar
  44. 44.
    Kawahara, N.; Kojoh, S.; Toda, Y.; Mizuno, A.; Kashiwa, N. The detailed analysis of the vinylidene structure of metallocenecatalyzed polypropylene. Polymer2004, 45, 355–357.CrossRefGoogle Scholar
  45. 45.
    Quevedo-Sanchez, B.; Henson, M. A.; Coughlin, E. B. Origin of the formation of the 4-butenyl end group in zirconocene-catalyzed propylene polymerization. J. Polym. Sci., Part A: Polym. Chem.2006, 44, 3724–3728.CrossRefGoogle Scholar
  46. 46.
    Resconi, L. On the mechanisms of growing-chain-end isomerization and transfer reactions in propylene polymerization with isospecific, C2-symmetric zirconocene catalysts. J. Mol. Catal. A: Chem.1999, 146, 167–178.CrossRefGoogle Scholar

Copyright information

© Chinese Chemical Society Institute of Chemistry, Chinese Academy of Sciences Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Simona Losio
    • 1
  • Laura Boggioni
    • 1
  • Massimiliano Cornelio
    • 1
  • Abbas Razavi
    • 2
  • Incoronata Tritto
    • 1
    Email author
  1. 1.CNR — Istituto di Scienze e Tecnologie Chimiche “G. Natta” (CNR-SCITEC)MilanoItaly
  2. 2.Total Petrochemicals Research, Zone Industrielle CFeluyBelgium

Personalised recommendations