e-Caprolactone / ZnCl2 complex formation: characterization and ring-opening polymerization mechanism
ε-Caprolactone (ε-CL) has been mixed with ZnCl2 at different mol ratios. The resulting complex was characterized through 1H and 13C NMR spectroscopy in bulk and in solutions, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and optical microscopy. Ring-opening polymeriza...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2000 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/35733 |
| Acceso en línea: | http://hdl.handle.net/11336/35733 |
| Access Level: | acceso abierto |
| Palabra clave: | Ring-Opening Polymerization Lactones Zinc Chloride Mechanism Quantum-Mechanical Calculation https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 https://purl.org/becyt/ford/2.5 https://purl.org/becyt/ford/2 |
| Sumario: | ε-Caprolactone (ε-CL) has been mixed with ZnCl2 at different mol ratios. The resulting complex was characterized through 1H and 13C NMR spectroscopy in bulk and in solutions, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and optical microscopy. Ring-opening polymerization of ε-caprolactone [M] using ZnCl2 as an initiator [I] at different monomer/initiator ratios has been successfully performed in xylene. The molecular weight of poly(ε-caprolactone) (PCL) as measured by gel permeation chromatografy (GPC) was found to depend linearly on the [M]/[I] ratio. Theoretical calculations were carried out to understand the geometry of the complex and the operating ring-opening mechanism. Both experimental and computational results and the presence of methylene–chloride end group, confirmed by NMR, are in agreement with a coordination–insertion mechanism for the ring-opening polymerization proposed in this article. |
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