Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases
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 tri...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | Macromol |
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| Online Access: | https://www.mdpi.com/2673-6209/2/2/16 |
| _version_ | 1797485108054196224 |
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| author | Julie Meimoun Audrey Favrelle-Huret Julien De Winter Philippe Zinck |
| author_facet | Julie Meimoun Audrey Favrelle-Huret Julien De Winter Philippe Zinck |
| author_sort | Julie Meimoun |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-09T23:14:03Z |
| format | Article |
| id | doaj.art-cacf3df3257b49d2a2cc226ecba73165 |
| institution | Directory Open Access Journal |
| issn | 2673-6209 |
| language | English |
| last_indexed | 2024-03-09T23:14:03Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Macromol |
| spelling | doaj.art-cacf3df3257b49d2a2cc226ecba731652023-11-23T17:40:10ZengMDPI AGMacromol2673-62092022-06-012223624610.3390/macromol2020016Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic BasesJulie Meimoun0Audrey Favrelle-Huret1Julien De Winter2Philippe Zinck3UMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, University of Lille, CNRS, Centrale Lille, University Artois, F-59650 Villeneuve d’Ascq, FranceUMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, University of Lille, CNRS, Centrale Lille, University Artois, F-59650 Villeneuve d’Ascq, FranceInterdisciplinary Center for Mass Spectrometry, Organic Synthesis and Mass Spectrometry Laboratory, University of Mons-UMONS, 23 Place du Parc, 7000 Mons, BelgiumUMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, University of Lille, CNRS, Centrale Lille, University Artois, F-59650 Villeneuve d’Ascq, FranceOrganocatalysis 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.https://www.mdpi.com/2673-6209/2/2/16polylactideorganocatalysisepimerizationchain scissionhydrolysis |
| spellingShingle | Julie Meimoun Audrey Favrelle-Huret Julien De Winter Philippe Zinck Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases Macromol polylactide organocatalysis epimerization chain scission hydrolysis |
| title | Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases |
| title_full | Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases |
| title_fullStr | Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases |
| title_full_unstemmed | Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases |
| title_short | Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases |
| title_sort | poly l lactide epimerization and chain scission in the presence of organic bases |
| topic | polylactide organocatalysis epimerization chain scission hydrolysis |
| url | https://www.mdpi.com/2673-6209/2/2/16 |
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