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Aspectos mecánicos de la polimerización del lactídeo con un sistema catalítico de aluminio de alta eficiencia
Carine Robert1, Thibault E Schmid1, Vincent Richard1
1Chimie ParisTech, PSL Research University, CNRS , Institut de Recherche de Chimie Paris, 75005 Paris, France.
Journal of the American Chemical Society
|April 12, 2017
Resumen
Un nuevo catalizador de aluminio, estabilizado por un ligando salen, inicia eficientemente la polimerización de apertura de anillo (ROP) de rac-lactida a temperatura ambiente. Este avance ofrece un método simple y de alto rendimiento para producir polilactido con propiedades controladas.
Área de la Ciencia:
- Química de los polímeros
- Química organometálica
- Catálisis
Sus antecedentes:
- La polimerización por apertura de anillos (ROP) es crucial para sintetizar polímeros biodegradables como el polilactido.
- El desarrollo de catalizadores altamente activos y accesibles para la ROP sigue siendo un objetivo de investigación importante.
- Los métodos existentes a menudo implican la preparación y purificación de catalizadores complejos.
Objetivo del estudio:
- Informar de un nuevo iniciador basado en aluminio altamente activo para el ROP de rac-lactida.
- Desarrollar un sistema catalítico simple y robusto para una síntesis eficiente de polilactidos.
- Elucidar el mecanismo de iniciación y propagación utilizando estudios computacionales.
Principales métodos:
- Generación in situ de un iniciador de aluminio estabilizado por un ligando saliente simétrico al C2.
- Polimerización de apertura de anillo (ROP) de rac-lactida utilizando el sistema de catalizador desarrollado.
- Estudios de la Teoría Funcional de la Densidad (DFT) para investigar el mecanismo de reacción.
Principales resultados:
- El complejo aluminio-saleno demostró una alta actividad sin precedentes para la ROP de raclactida a temperatura ambiente.
- El sistema catalizador, preparado a partir de un complejo de sal y una sal de cebolla, proporcionó polilactido en buenos rendimientos.
- Se obtuvieron índices estrechos de polidispersidad, lo que indica una polimerización controlada.
- Los estudios DFT confirmaron el ataque externo de alcóxidos al monómero coordinado durante la iniciación y la propagación.
Conclusiones:
- Se ha desarrollado un sistema catalítico altamente eficiente y accesible para la síntesis de polilactidos.
- El nuevo método evita la preparación compleja y costosa del catalizador, lo que lo hace industrialmente relevante.
- Las ideas mecanicistas proporcionan una base para el diseño de futuros catalizadores de polimerización.
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