| Autor: |
Julie Meimoun, Audrey Favrelle-Huret, Julien De Winter, Philippe Zinck |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Macromol, Vol 2, Iss 2, Pp 236-246 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2673-6209 |
| DOI: |
10.3390/macromol2020016 |
| Popis: |
Organocatalysis for polymer chemistry has become a subject of significant interest in the last two decades. In this contribution, we have studied the evolution of the microstructure of poly(L-lactide) in solution in toluene at 105 °C in the presence of various organocatalysts. Weak bases such as triethylamine and DMAP (4-dimethylaminopyridine) lead to a low extent of epimerization and a chain scission reaction. The DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) amidine induces in turn important extents of both epimerization (up to 37% D-stereoisomer formation) and chain scission. This has been tentatively attributed to a nucleophilic mechanism. Cinchona alkaloids lead to only a modest amount of epimerization. Phosphazene bases are in turn rather active, especially for high catalytic loadings (>1 mol %). The chain scission observed in this case is proposed to occur via a base-catalyzed hydrolysis mechanism. Finally, it is shown that combining an organic base with an acid can lead to a synergistic effect regarding notably the chain scission reaction. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
