Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-625271
Polycondensation of L-lactic acid: a deeper look into solid state polycondensation
- L-Lactic acid (LA) was condensed in the presence of SnCl2 or 4-toluenesulfonic acid (TSA) at 140 °C, and chain growth without cyclization was observed. In addition, poly(L-lactic acid)s (PLAs) with a degree of polymerization (DP) of 25, 50 or 100 were prepared by water-initiated ring-opening polymerization (ROP). These PLAs were annealed in the solid state at 140 °C and 160 °C in the presence of tin(II) 2-ethylhexanoate (SnOct2, SnCl2 or TSA). The changes in the molar mass distribution and in the topology were characterized by means of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and size exclusion chromatography (SEC). With increasing time, fewer side reactions caused higher molar masses and increasing fractions of cyclic polylactides (cPLA) were obtained. Their “saw tooth” pattern in the MALDI-TOF mass spectra indicated the formation of extended ring crystallites in the solid state. TSA was the most active catalyst and caused fewer sideL-Lactic acid (LA) was condensed in the presence of SnCl2 or 4-toluenesulfonic acid (TSA) at 140 °C, and chain growth without cyclization was observed. In addition, poly(L-lactic acid)s (PLAs) with a degree of polymerization (DP) of 25, 50 or 100 were prepared by water-initiated ring-opening polymerization (ROP). These PLAs were annealed in the solid state at 140 °C and 160 °C in the presence of tin(II) 2-ethylhexanoate (SnOct2, SnCl2 or TSA). The changes in the molar mass distribution and in the topology were characterized by means of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and size exclusion chromatography (SEC). With increasing time, fewer side reactions caused higher molar masses and increasing fractions of cyclic polylactides (cPLA) were obtained. Their “saw tooth” pattern in the MALDI-TOF mass spectra indicated the formation of extended ring crystallites in the solid state. TSA was the most active catalyst and caused fewer side reactions than SnCl2, which was the least reactive catalyst. Acetylation of the CH-OH end groups hindered polycondensation and prevented the formation of cPLAs. Reaction mechanisms will be discussed.…


| Autor*innen: | Hans R. Kricheldorf, Steffen WeidnerORCiD, Felix Scheliga |
|---|---|
| Dokumenttyp: | Zeitschriftenartikel |
| Veröffentlichungsform: | Verlagsliteratur |
| Sprache: | Englisch |
| Titel des übergeordneten Werkes (Englisch): | Polymer Chemistry |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 6 Materialchemie |
| 6 Materialchemie / 6.3 Strukturanalytik | |
| Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
| Verlag: | Royal Society of Chemistry (RSC) |
| Erste Seite: | 1 |
| Letzte Seite: | 9 |
| DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
| Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten | |
| Freie Schlagwörter: | MALDI-TOF MS; Polycondensation; Polylaktide; Solid state |
| Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
| Chemie und Prozesstechnik / Chemische Charakterisierung und Spurenanalytik | |
| Material | |
| Material / Degradationsmechanismen | |
| DOI: | 10.1039/d4py01191k |
| URN: | urn:nbn:de:kobv:b43-625271 |
| ISSN: | 1759-9962 |
| Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
| Lizenz (Deutsch): | Creative Commons - CC BY-NC - Namensnennung - Nicht kommerziell 4.0 International |
| Datum der Freischaltung: | 10.02.2025 |
| Referierte Publikation: | Ja |
| Datum der Eintragung als referierte Publikation: | 10.02.2025 |
| Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |


