Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-595541
Cyclic polyglycolides via ring-expansion polymerization with cyclic tin catalysts
- Glycolide was polymerized in bulk with two cyclic catalysts − 2,2-dibutyl-2-stanna-1,3-dithiolane (DSTL) and 2-stanna-1,3-dioxa-4,5,6,7-dibenzepane (SnBiph). The monomer/initiator ratio, temperature (140 – 180 °C) and time (1–––4 days) were varied. The MALDI TOF mass spectra exclusively displayed peaks of cyclic polyglycolide (PGA) and revealed an unusual “saw-tooth pattern” in the mass range below m/z 2 500 suggesting formation of extended ring crystallites. The DSC measurements indicated increasing crystallinity with higher temperature and longer time, and after annealing for 4 d at 160 °C a hitherto unknown and unexpected glass transition was found in the temperature range of 170–185 °C. Linear PGAs prepared by means of metal alkoxides under identical conditions did not show the afore-mentioned features of the cyclic PGAs, neither in the mass spectra nor in the DSC measurements. All PGAs were also characterized by SAXS measurements, which revealed relatively small L-valuesGlycolide was polymerized in bulk with two cyclic catalysts − 2,2-dibutyl-2-stanna-1,3-dithiolane (DSTL) and 2-stanna-1,3-dioxa-4,5,6,7-dibenzepane (SnBiph). The monomer/initiator ratio, temperature (140 – 180 °C) and time (1–––4 days) were varied. The MALDI TOF mass spectra exclusively displayed peaks of cyclic polyglycolide (PGA) and revealed an unusual “saw-tooth pattern” in the mass range below m/z 2 500 suggesting formation of extended ring crystallites. The DSC measurements indicated increasing crystallinity with higher temperature and longer time, and after annealing for 4 d at 160 °C a hitherto unknown and unexpected glass transition was found in the temperature range of 170–185 °C. Linear PGAs prepared by means of metal alkoxides under identical conditions did not show the afore-mentioned features of the cyclic PGAs, neither in the mass spectra nor in the DSC measurements. All PGAs were also characterized by SAXS measurements, which revealed relatively small L-values suggesting formation of thin crystallites in all cases with little influence of the reaction conditions.…
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| Autor*innen: | Steffen Weidner, A. Meyer, H. Kricheldorf |
|---|---|
| Dokumenttyp: | Zeitschriftenartikel |
| Veröffentlichungsform: | Verlagsliteratur |
| Sprache: | Englisch |
| Titel des übergeordneten Werkes (Englisch): | European Polymer Journal |
| Jahr der Erstveröffentlichung: | 2024 |
| Organisationseinheit der BAM: | 6 Materialchemie |
| 6 Materialchemie / 6.3 Strukturanalytik | |
| Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
| Verlag: | Elsevier Ltd. |
| Jahrgang/Band: | 207 |
| Aufsatznummer: | 112811 |
| Erste Seite: | 1 |
| Letzte Seite: | 9 |
| Freie Schlagwörter: | Crystals; MALDI-TOF MS; Polyglycolide; Ring-expansion polymerization |
| Themenfelder/Aktivitätsfelder der BAM: | Material |
| Material / Materialdesign | |
| DOI: | 10.1016/j.eurpolymj.2024.112811 |
| URN: | urn:nbn:de:kobv:b43-595541 |
| ISSN: | 0014-3057 |
| Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
| Lizenz (Deutsch): |  Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International |
| Datum der Freischaltung: | 22.02.2024 |
| Referierte Publikation: | Ja |
| Datum der Eintragung als referierte Publikation: | 08.04.2024 |
| Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |
