[en] Aluminum isopropoxide is an effective initiator for the polymerization of lactides in toluene at 70-degrees-C. The ring-opening polymerization proceeds through a "coordination-insertion" mechanism and selective rupture of the acyl oxygen bond of the monomer. A kinetic study has shown that the polymerization is first order in both the monomer and initiator. The polymerization is typically "living" until a molecular weight of ca. 90 000 is reached. At higher temperatures (100-degrees-C), inter- and intramolecular transesterification reactions are responsible for a limitation in the molecular weight of the growing chains. In toluene, at 70-degrees-C, each alkoxide of the aluminum isopropoxide participates in the polymerization. Any molecular weight below 90 000 can accordingly be predicted on the basis of the monomer/Al molar ratio, and the polydispersity is rather narrow (1.1-1.4).
Research center :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Materials science & engineering Chemistry
Author, co-author :
Dubois, Philippe; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Jacobs, R.; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Jérôme, Robert ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Teyssié, Philippe ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Language :
English
Title :
Macromolecular engineering of polylactones and polylactides. 4. Mechanism and kinetics of lactide homopolymerization by aluminum isopropoxide
Publication date :
29 April 1991
Journal title :
Macromolecules
ISSN :
0024-9297
eISSN :
1520-5835
Publisher :
American Chemical Society, Washington, United States - District of Columbia
BELSPO - Politique scientifique fédérale [BE] IRSIA - Institut pour l'Encouragement de la Recherche Scientifique dans l'Industrie et l'Agriculture [BE]
Gogolewski, S.; Pennings, A. J. Makromol. Chem., Rapid Commun. 1982, 3, 839.
Pitt, C. G.; Marks, T. A.; Schindler, A. In Biodegradable Drug Delivery Systems Based on Aliphatic Polyesters: Application of Contraceptives and Narcotic Antagonists, Controlled Release of Bioactive Materials; Baker, R., Ed.; Academic Press: New York, 1980.
Schindler, A.; Jeffcoat, R.; Kimmel, G. L.; Pitt, C. G.; Wall, M. E.; Zweidinger, R. Contemporary Topics in Polymer Science; Pearce, E. M, Schaefgen, J. R., Eds.; Plenum Press: New York, 1977; Vol. 2, p 251.
Gogolewski, S.; Pennings, A. J. Makromol. Chem., Rapid Commun. 1983, 4, 673.
Vert, M.; Chabot, F. Markromol. Chem., Suppl. 1980, 5, 30.
Rak, J.; Ford, J. L.; Rostron, C.; Walters, V. Pharm. ActaHelv. 1985, 60, 162.
Peckham, G. T.; Filichioni, E. M. In Kirk-Othmer Encyclopedia of Chemical Technology, 2nd ed.; Wiley: New York, 1967; Vol. 12, p 170.
Lowe, C. E. (Du Pont) U.S. Pat. 2668162, 1954.
Chabot, F.; Vert, M.; Chapelle, S.; Granger, P. Polymer 1983, 24, 53.
Teeters, W. O. (Du Pont) U.S. Pat. 2363511, 1945.
Tonelli, A. E.; Flory, P. J. Macromolecules 1969, 2, 225.
Lillie, E.; Schulz, R. C. Makromol. Chem. 1975, 176, 1901.
Kricheldorf, H. R.; Sumbel, M. Eur. Polym. J. 1989, 25, 585.
Deasy, P. B.; Finan, M. P.; Meegan, M. J. J. Microencapsulation 1989, 6, 369.
Leenslag, J. W.; Pennings, A. J. Makromol. Chem. 1987, 188, 1809.
Van Dijk, J. A. P. P.; Smit, J. A. M.; Kohn, F. E.; Feijen, J. J. Polym. Sci, Polym. Chem. Ed. 1983, 21, 197.
Kohn, F. E.; Van Ommen, J. G.; Feijen, J. Eur. Polym. J. 1983, 19, 1081.
Kricheldorf, H. R.; Berl, M.; Scharnagl, N. Macromolecules 1988, 21, 286.
Hamitou, A.; Ouhadi, T.; Jerome, R.; Teyssie, P. J. Polym. Sci., Polym.Chem. Ed. 1977, 15, 865.
Hamitou, A.; Jerome, R.; Hubert, A. J.; Teyssie, P. Macromolecules 1973, 6, 651.
Heuschen, J.; Jerome, R.; Teyssie, P. Macromolecules 1981, 14, 242.
Jerome, R.; Teyssie, P. Comprehensive Polymer Science; Eastmond, G. C., Ledwith, A., Russo, S., Sigwalt, P., Eds.; Pergamon Press: New York, 1989; Vol. 3, p 501.
Song, C. X.; Feng, X. D. Macromolecules 1984, 17, 2764.
Yasuda, Y.; Aida, T.; Inoue, S. Macromolecules 1984, 17, 2217.
Enco, M.; Aida, T.; Inoue, S. Macromolecules 1987, 20, 2982.
Trofimoff, L.; Aida, T.; Inoue, S. Chem. Lett. 1987, 991.