Abstract
We describe the synthesis of a styrene–ethylene copolymer using a trivalent titanium-based polymerization catalyst system, tris(acetylacetonate)titanium (Ti(acac)3), combined with triisobutylaluminum-modified methylaluminoxane. Gel-permeation chromatography measurement revealed that copolymerization using the above-mentioned catalyst system yielded a mixture of two different polymers. 13C nuclear magnetic resonance (NMR) analysis of the Soxhlet-extracted fractions indicated that the insoluble part contained a long ethylene–ethylene sequence and an isolated styrene unit, whereas the soluble part contained a syndiotactic styrene–styrene sequence with ethylene units adjacent to continuous styrene units. The ratio of the styrene–styrene sequence to the styrene–ethylene joint part of the Soxhlet-soluble fraction, estimated from the NMR resonances, increased with the styrene content. The melting temperature of the Soxhlet-soluble fraction also increased with the (styrene–styrene)/(styrene–ethylene) ratio of the polymers. These two results together indicate that a block-like copolymer was produced that contained long syndiotactic polystyrene portions separated by ethylene units.
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References
Ishihara, N., Seimiya, T., Kuramoto, M. & Uoi, M. Crystalline syndiotactic polystyrene. Macromolecules 19, 2464–2465 (1986).
Ishihara, N., Kuramoto, M. & Uoi, M. Stereospecific polymerization of styrene giving the syndiotactic polymer. Macromolecules 21, 3356–3360 (1988).
Po, R. & Cardi, N. Synthesis of syndiotactic polystyrene: reaction mechanism and catalysis. Prog. Polym. Sci. 21, 47–88 (1996).
Schellenberg, J. & Tomatsu, N. Syndiotactic polystyrene catalysts and polymerization. Prog. Polym. Sci. 27, 1925–1982 (2002).
Schellenberg, J. Recent transition metal catalysts for syndiotactic polystyrene. Prog. Polym. Sci. 34, 688–718 (2009).
Tomotsu, N., Isihara, N., Newman, T. H. & Malanga, M. T. Syndiospecific polymerization of styrene. J. Mol. Catal. A 128, 167–190 (1998).
Aaltonen, P. & Seppala, T. Copolymerization of styrene and ethylene with monocyclopentadienyltitanium trichloride/methylaluminoxane catalyst. Characterization of the product. Eur. Polym. J. 30, 683–687 (1994).
Yokota, K., Kohsaka, T., Ito, K. & Ishihara, N. Consideration of the mechanism of styrene/ethylene copolymerization with half-titanocene catalysts. J. Polym. Sci. Part A: Polym. Chem. 43, 5041–5048 (2005).
Nomura, K., Komatsu, T. & Imanishi, Y. Syndiospecific styrene polymerization and efficient ethylene/styrene copolymerization catalyzed by (cyclopentadienyl)(aryloxy)titanium(IV) complexes—MAO system. Macromolecules 33, 8122–8124 (2000).
Nomura, K., Okumura, H., Komatsu, T. & Naga, N. Ethylene/styrene copolymerization by various (cyclopentadienyl)(aryloxy)titanium(IV) complexes—MAO catalyst system. Macromolecules 35, 5388–5395 (2002).
Zhang, H. & Nomura, K. Living copolymerization of ethylene with styrene catalyzed by (cyclopentadienyl)(ketimide)titanium(IV) complex—MAO catalyst system. J. Am. Chem. Soc. 127, 9364–9365 (2005).
Zhang, H. & Nomura, K. Living copolymerization of ethylene with styrene catalyzed by (cyclopentadienyl)(ketimide)titanium(IV) complex—MAO catalyst system: Effect of anionic ancillary donor ligand. Macromolecules 39, 5266–5274 (2006).
Zhang, H., Byun, D. J. & Nomura, K. Tuning the active species from syndiospecific styrene polymerisation to ethylene/styrene copolymerisation by (aryloxo)(cyclopentadienyl)titanium complexes—MAO catalysts. Dalton Tans. 18, 1802–1806 (2007).
Sernetz, F. G., Mulhaupt, R., Fokken, S. & Okuda, J. Copolymerization of ethene with styrene using methylaluminoxane-activated Bis(phenolate) complexes. Macromolecules 30, 1562–1569 (1997).
Guo, N., Stern, C. L. & Marks, T. J. Bimetallic Effects in the Homopolymerization of Styrene and Copolymerizationof Ethylene and StyrenicComonomers. Scope, Kinetics, and Mechanism. J. Am. Chem. Soc. 130, 2246–2261 (2008).
Son, K. S., Joge, F. & Waymouth, R. Copolymerization of styrene and ethylene at high temperature with titanocenes containing a pendant amine donor. M. Macromolecules 41, 9663–9668 (2008).
Son, K. S. & Waymouth, R. M. Stereospecific styrene polymerization and ethylene–styrenecopolymerization with titanocenes containing a pendant amine donor. J. Polym. Sci. Part A: Polym. Chem. 48, 1579–1585 (2010).
Luo, Y. J., Baldamus, J. & Hou, Z. M. Scandium half-metallocene-catalyzed syndiospecific styrene polymerization and styreneethylene copolymerization: unprecedented incorporation of syndiotactic styrenestyrene sequences in styreneethylene copolymers. J. Am. Chem. Soc. 126, 13910–13911 (2004).
Rodrigues, A. S., Kirillov, E., Lehmann, C. W., Roisnel, T., Vuillemin, B., Razavi, A. & Carpentier, J. F. Allylansa-lanthanidocenes: single-component, single-site catalysts for controlled syndiospecific styrene and styrene–ethylene (Co)polymerization. Chemistry 13, 5548–5565 (2007).
Zambelli, A., Pellecchia, C., Longo, P., Grassi, A. & Oliva, L. Catalysts for syndiotactic-specific polymerization of styrene—a tentative interpretation of some experience data. Makromol. Chem. 192, 223–231 (1991).
Longo, P., Proto, A. & Zambelli, A. Syndiotacitc specific polymerization of styrene—driving energy of the steric control and reaction-mechanism. Macromol. Chem. Phys. 196, 3015–3029 (1995).
Grassi, A., Pellecchia, C., Oliva, L. & Laschi, F. A combined NMR and electron spin resonance investigation of the (C5(CH3)5)Ti(CH2C6H5)3/B(C6F5)3 catalytic system active in the syndiospecific styrene polymerization. Macromol. Chem. Phys. 196, 1093–1100 (1995).
Grassi, A., Zambelli, A. & Laschi, F. Reductive decomposition of cationic half-titanocene(IV) complexes, precursors of the active species in syndiospecific styrene polymerization. Organometallics 15, 480–482 (1996).
Grassi, A., Lamberti, C., Zambelli, A. & Mingozzi, I. Syndiospecific styrene polymerization promoted by half-titanocene catalysts: a kinetic investigation providing a closer insight to the active species. Macromolecules 30, 1884–1889 (1997).
Grassi, A., Saccheo, S., Zambelli, A. & Laschi, F. Reactivity of the [(eta(5)-C5Me5)TiCH3][RB(C6F5)3] complexes identified as active species in syndiospecific styrene polymerization. Macromolecules 31, 5588–5591 (1998).
Mahanthappa, M. M. & Waymouth, R. M. Titanium-mediated syndiospecific styrene polymerizations: role of oxidation state. J. Am. Chem. Soc. 123, 12093–12094 (2001).
Ewart, S. W., Sarsfield, M. J., Jeremic, D., Tremblay, T. L., Williams, E. F. & Baird, M. C. Ethylene and propylene polymerization by highly electrophilic, chiral monocyclopentadienyl titanium catalysts. Organometallics 17, 1502–1510 (1998).
Ewart, S. W., Sarsfield, M. J., Williams, E. F. & Baird, M. C. Ethylene and propylene polymerization by cationic monocyclopentadienyl titanium catalysts containing the weakly coordinating anion [B(C6F5)4]. J. Organomet. Chem. 579, 106–113 (1999).
Williams, E. F., Murray, M. C. & Baird, M. C. Oxidation state(s) of the active titanium species during polymerization of styrene to syndiotactic polystyrene catalyzed by Cp*TiMe3/B(C6F5)3, Cp*TiMe3/[Ph3C][B(C6F5)4], and Cp*TiCl2,3/MAO. Macromolecules 33, 261–268 (2000).
Bryliakov, K. P., Semikolenova, N. S., Zakharov, V. A. & Talsi, E. P. 13C-NMR study of Ti(IV) species formed by Cp*TiMe3 and Cp*TiCl3 activation with methylaluminoxane (MAO). J. Organomet. Chem. 683, 23–28 (2003).
Napoli, M., Grisi, F. & Longo, P. Half-titanocene-based catalysts in the syndiospecific polymerization of styrenes: possible oxidation states of the titanium species and geometries of the active sites. Macromolecules 42, 2516–2522 (2009).
Brintzinger, H. H., Fischer, D., Mulhaupt, R., Rieger, B. & Waymouth, R. M. Stereospecific olefin polymerization with chiral metallocene catalysts. Angew. Chem. Int. Ed. Engl. 34, 1143–1170 (1995).
Nomura, K. Syndiospecific styrene polymerization and ethylene/styrene copolymerization using falf-titanocenes: ligand effects and some mechanistic aspects. Catal. Sur. Asia 14, 33–49 (2010).
Capacchione, C., De Carlo, F., Zannoni, C., Okuda, J. & Proto, A. Propylenestyrene multiblock copolymers: evidence for monomer enchainment via opposite insertion regiochemistry by a single-site catalyst. Macromolecules 37, 8918–8922 (2004).
Ricciardi, R., Napoli, M. & Longo, P. Facile synthesis of blocky styrene(1,3)-butadiene copolymers having stereoregular monomeric sequences. J. Polym. Sci. Part A: Polym. Chem. 48, 815–822 (2010).
Zambelli, A., Oliva, L. & Pellecchia, C. Soluble catalysts for syndiotactic polymerization of styrene. Macromolecules 22, 2129–2130 (1989).
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Hagihara, H., Usui, C. & Naga, N. Synthesis of ethylene–styrene copolymer containing syndiotactic polystyrene sequence by trivalent titanium catalyst. Polym J 44, 147–154 (2012). https://doi.org/10.1038/pj.2011.109
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DOI: https://doi.org/10.1038/pj.2011.109
