Poly(Epsilon-caprolactone) by combined ring-opening polymerization and azeotropic polycondensation - the role of cyclization and equilibration
- Using three different catalysts, water-initiated polymerizations of ε-caprolactone were conducted in bulk with variation of the monomer/water ratio. The resulting CH2OH and CO2H- terminated polylactones were subjected in situ to azeotropic polycondensations. With Bi-triflate and temperatures, the polycondensations were not much successful and involved side reactions. With ZnCl2, and especially SnCl2, considerably higher molar masses were achieved. The substitution of toluene for chlorobenzene for refluxing gave better results. The polycondensations broadened the molar mass distribution of the ROP-based prepolymers, and polydispersities between 1.4–1.8 were obtained. The MALDITOF mass spectra revealed that the polycondensations significantly enhanced the fraction of rings due to efficient 'end-biting' reactions. By comparison with copolymerization experiments and Sn methoxide-initiated polymerizations, it was demonstrated that equilibration reactions, such as the formation of rings byUsing three different catalysts, water-initiated polymerizations of ε-caprolactone were conducted in bulk with variation of the monomer/water ratio. The resulting CH2OH and CO2H- terminated polylactones were subjected in situ to azeotropic polycondensations. With Bi-triflate and temperatures, the polycondensations were not much successful and involved side reactions. With ZnCl2, and especially SnCl2, considerably higher molar masses were achieved. The substitution of toluene for chlorobenzene for refluxing gave better results. The polycondensations broadened the molar mass distribution of the ROP-based prepolymers, and polydispersities between 1.4–1.8 were obtained. The MALDITOF mass spectra revealed that the polycondensations significantly enhanced the fraction of rings due to efficient 'end-biting' reactions. By comparison with copolymerization experiments and Sn methoxide-initiated polymerizations, it was demonstrated that equilibration reactions, such as the formation of rings by 'back-biting,' did not occur.…
MetadatenAutor*innen: | H.R. Kricheldorf, Steffen WeidnerORCiD, F. Scheliga |
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Dokumenttyp: | Zeitschriftenartikel |
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Veröffentlichungsform: | Verlagsliteratur |
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Sprache: | Englisch |
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Titel des übergeordneten Werkes (Englisch): | Journal of polymer science A, polymer chemistry |
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Jahr der Erstveröffentlichung: | 2012 |
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Verlag: | Wiley |
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Verlagsort: | Hoboken, NJ |
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Jahrgang/Band: | 50 |
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Ausgabe/Heft: | 20 |
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Erste Seite: | 4206 |
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Letzte Seite: | 4214 |
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Freie Schlagwörter: | Cyclization; Epsilon-caprolactone (e-CL); MALDI-TOF mass spectrometry; Polycondensation; Polyesters; Ring-opening polymerization |
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DOI: | 10.1002/pola.26222 |
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ISSN: | 0360-6376 |
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ISSN: | 0887-624X |
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Verfügbarkeit des Dokuments: | Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access") |
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Bibliotheksstandort: | Sonderstandort: Publica-Schrank |
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Datum der Freischaltung: | 19.02.2016 |
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Referierte Publikation: | Ja |
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Datum der Eintragung als referierte Publikation: | 19.09.2012 |
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