Ring-Expansion Polymerization (REP) of L-lactide with cyclic Tin(II) Bisphenoxides
- Five new cyclic catalysts were prepared by a new synthetic method from tin(II)-2-ethyhexanoate and silylated catechols, silylated 2,2´dihydroxybiphenyl or silylated 1,1´-bisnaphthol. These catalysts were compared with regard to their usefulness as catalysts for the ring expansion polymerization (REP) of L-lactide in bulk at 160 °C, and with two different tin(IV) derivatives of 1,1´binaphthol. Best results were obtained using seven-membered cyclic tin(II)bisphenoxides, which yielded colorless cyclic poly(l-lactide)s free of racemization with weight average molecular weights (Mw) up to 305 000 g mol-1. Furthermore, these catalysts were active even at a lactide/catalyst ratio of 20 000/1. Our new results were superior to those obtained from all other previously published catalysts yielding cyclic poly(L-lactide). The seven-membered cycles also proved to be more active than tin(II) 2-ethylhexanoate with and without the addition of alcohol.
Autor*innen: | Hans Kricheldorf, Steffen WeidnerORCiD, Felix Scheliga |
---|---|
Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | European Polymer Journal |
Jahr der Erstveröffentlichung: | 2019 |
Organisationseinheit der BAM: | 6 Materialchemie |
6 Materialchemie / 6.3 Strukturanalytik | |
Verlag: | Elsevier Ltd. |
Jahrgang/Band: | 116 |
Erste Seite: | 256 |
Letzte Seite: | 264 |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Cyclization; Lactide; MALDI-TOF MS; Ring-expansion polymerization; Tin(II)octanoate |
Themenfelder/Aktivitätsfelder der BAM: | Material |
DOI: | 10.1016/j.eurpolymj.2019.04.024 |
ISSN: | 0014-3057 |
ISSN: | 1873-1945 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 17.04.2019 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 05.07.2019 |