Abstract
Propene polymerization was conducted with TiCl4/(Lewis base)/MgCl2-Cp2TiMe2 catalysts in the presence of ethyl benzoate (EB) and/or 2,2-diisobutyl-1,3-dimethoxypropane (DBDMP). The addition of small amounts of these Lewis bases to MgCl2 before supporting TiCl4 decreased the amount of Ti in the catalyst and improved catalyst isospecificity. The results suggested that the Lewis base is selectively coordinated on the MgCl2 surface where aspecific sites had been formed. The addition of the Lewis bases during the polymerization increased polymerization rate followed by rapid deactivation. Deactivation was second order on the polymerization rate and the deactivation rate constant depended on both structure and amount of the Lewis base. GPC analysis of the produced polymers indicated that the addition of the Lewis bases increased the molecular weight of isotactic polypropene (IPP). Polydispersity depended on the Lewis base: it became narrower by EB and broader by DBDMP. The 13C NMR spectra of IPPs revealed that EB improved the microtacticity of IPP more effectively than DBDMP. ESR spectra of the catalysts indicated that the amount of isolated Ti3+ species increased in the presence of EB.
Similar content being viewed by others
Article PDF
References
V. Busico, P. Corradini, L. D. Martino, A. Proto, V. Savino, and E. Albizzati, Makromol. Chem., 186, 1279 (1985).
K. Soga, J. R. Park, and T. Shiono, Makromol. Chem., Rapid Commun., 11, 117 (1990).
A. Proto, L. Oliva, C. Pellecchia, A. J. Sivak, and L. A. Cullo, Macromolecules, 23, 2904 (1990).
K. Soga, T. Shiono, and Y. Doi, Makromol. Chem., 189, 1531 (1988).
M. Kioka and N. Kashiwa, J. Mol. Catal., 82, 11 (1993).
R. Ohnishi, H. Funabashi, and A. Tanaka, Makromol. Chem., Rapid Commun., 12, 19 (1991).
V. K. Gupta, S. Satish, and I. S. Bhardwa, Eur. Polym. J., 28, (1992).
E. Iiskoa and A. Pelkonen, Makromol. Chem., Rapid Commun., 14, 133 (1993).
E. Albizzati, T. Dallocco, M. Galimberti, and G. Morini, “Catalyst Design for Tailor-Made Polyolefins,” K. Soga and M. Terano, Ed., Kodansha-Elsevier, Tokyo, 1994, p 139.
Hercules, Inc., U.S. Patent 4408019 (1983), inv. H. W. Bunt.
Chem. Abstr., 100, 7417h (1983).
Japan (open), 57, 111307.
Hercules, Inc., inv. G. A. Lock, Chem. Abstr., 101, 132232r (1984).
K. Soga, T. Uozumi, and T. Shiono, Makromol. Chem., Rapid Commun., 10, 293 (1989).
Himont Inc., EP 361494 (1990), invs. E. Albizzati, P. C. Barbe, L. Noristi, R. Scordamaglia, L. Barino, U. Giannini, and G. Morini.
Chem. Abstr., 113, 153260m (1990).
J. C. W. Chein and W. Jiun-chen, J. Polym. Sci., Part A: Polym. Chem., 20, 2461 (1982).
S. A. Sergeev, V. A. Poluboyarov, V. A. Zakharov, V. F. Anufrienko, and G. D. Bukatov, Makromol. Chem., 186, 243 (1985).
P. Brant and E. G. M. Tornqvist, Inorg. Chem., 25, 3776 (1986).
V. Busico, P. Corradini, L. D. Martino, A. Proto, and E. Albizzati, Makromol. Chem., 187, 1115 (1986).
The interaction between Cp2TiMe2 and Lewis base was investigated by 90 MHz 1H NMR in C6D6 at room temperature. The chemical shifts of Cp2TiMe2, EB, and DBDMP were observed before and after mixing Cp2TiMe2 with these Lewis bases. The results proved that the chemical shifts of these compounds were almost unchanged before and after mixing.
M. Galimberti, F. Piemontesi, U. Giallini, and E. Albizzati, Macromolecules, 26, 6771 (1990).
V. Busico, R. Cipullo, P. Corradini, and R. D. Biasio, Makromol. Chem. Phys., 196, 491 (1995).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hagihara, H., Shiono, T., Ikeda, T. et al. Additive Effects of Lewis Bases on Propene Polymerization over MgCl2-Supported TiCl4 Catalysts Combined with Cp2TiMe2. Polym J 29, 224–229 (1997). https://doi.org/10.1295/polymj.29.224
Issue Date:
DOI: https://doi.org/10.1295/polymj.29.224