Bismuth halide‐catalyzed polymerizations of ε‐caprolactone |
| |
| Authors: | Mohammed Lahcini Gert Schwarz Hans R Kricheldorf |
| |
| Institution: | 1. Laboratoire de Chimie Bioorganique et Macromoléculaire, Faculté des Sciences et Techniques Marrakech, Bld Abdelkarim Khattabi, 40000 Marrakech, Maroc;2. Institut für Technische und Makromolekulare Chemie der Universit?t Hamburg, Bundesstr. 45, D‐20146 Hamburg, Germany |
| |
| Abstract: | In contrast to BiF3, the other three Bi‐halides catalyzed the ring‐opening polymerization of ε‐caprolactone (ε‐CL) in bulk. A temperature of 140 °C was found to be advantageous for rapid polymerization and optimum molecular weights. At this temperature, the reactivity of the catalysts increases in the order BiCl3 < BiBr3 < BiJ3. Variation of the monomer‐catalyst ratio (M/C) yielded number‐average molecular weights (Mns) up to 80,000 Da (corrected SEC data, 120,000 Da uncorrected), but a proper control of the Mns was not achieved. In addition to CH2? OH endgroups, CH2Cl, CH2Br, and CH2J endgroups were detected, but no evidence for a cationic polymerization mechanism was found. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7483–7490, 2008 |
| |
| Keywords: | biodegradable polyesters bismuth chloride bismuth iodide ε ‐caprolactone gel permeation chromatography ring‐opening polymerization |
|
|
