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- Title
Poly( ϵ-caprolactone) by Combined Ring-Opening Polymerization and Polycondensation.
- Authors
Kricheldorf, Hans R.; Weidner, Steffen M.; Scheliga, Felix; Lahcini, Mohammed
- Abstract
Numerous water-initiated polymerizations of ϵCL are conducted in bulk with variation of catalyst, reaction time, and temperature. The conversions are determined by 1H NMR and the molar masses by SEC measurements. For polymerizations at 100 °C, Bi triflate and Hf triflate are used as catalysts, whereas at 140 °C, Al triflate, Sn(II) triflate, SnCl2, HfCl4, BiCl3, and LaCl3 are used. In addition to a closed reaction vessel, experiments are also performed with stirring in a vacuum. Under these conditions, the best catalyst (SnCl2) yields 2-3 times higher molar masses and mass spectra indicate a significant higher fraction of cyclic polymers. The results prove that a modification of the procedure may stimulate a polycondesation process without change of catalyst, time, and temperature.
- Publication
Macromolecular Chemistry & Physics, 2012, Vol 213, Issue 14, p1482
- ISSN
1022-1352
- Publication type
Article
- DOI
10.1002/macp.201200061