Poly(ϵ-caprolactone) by Combined Ring-Opening Polymerization and Polycondensation

• Published in: Macromolecular chemistry and physics Vol. 213; no. 14; pp. 1482 - 1488
• Main Authors: Kricheldorf, Hans R., Weidner, Steffen M., Scheliga, Felix, Lahcini, Mohammed
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 26.07.2012; WILEY‐VCH Verlag; Wiley
• Subjects: Applied sciences; cyclization; Exact sciences and technology; MALDI-TOF mass spectrometry; Organic polymers; Physicochemistry of polymers; Polycondensation; polycondensations; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; ring-opening polymerizations; ϵ-Caprolactone; Ring opening polymerization; Intramolecular reaction; One pot reaction; ε-Caprolactone; Bulk polymerization; Self condensation; Telechelic polymer; Metal Chlorides; ring-opening polymerizations; Temperature effect; Condensation polymerization; Experimental study; Sulfonate; Cyclization; MALDI-TOF mass spectrometry; Mineral salt; Catalyst activity; Polycaprolactone; Comparative study; polycondensations
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.201200061

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. The water‐initiated polymerization of ϵ‐caprolactone is catalyzed by various metals salts. The resulting macromers are subjected to polycondensation in vacuo. The catalysts are optimized for a “one‐pot procedure”.