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Estrellas polilactídicas centradas en el tris ((dibenzoilmetano) de hierro: múltiples funciones para el complejo
Jessica L Gorczynski1, Jianbin Chen, Cassandra L Fraser
1Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
Journal of the American Chemical Society
|October 27, 2005
Resumen
Los complejos de hierro mejoran la síntesis de poli (ácido láctico). El uso de hierro (III) como grupo protector y catalizador redujo significativamente los tiempos de reacción y mejoró el control del peso molecular en la polimerización de lactida, produciendo biomateriales avanzados.
Área de la Ciencia:
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- Ciencia de los materiales Ciencia de los materiales.
- La catálisis de la catálisis.
Sus antecedentes:
- El ácido poli (ácido láctico) (PLA) y sus complejos metálicos son prometedores como biomateriales y catalizadores.
- La polimerización tradicional de lactida utilizando Sn(oct) 2 con iniciadores de dibenzoilmetano (dbmOH) funcionalizado con hidroxilo es lenta y ofrece un control limitado del peso molecular.
Objetivo del estudio:
- Para mejorar la eficiencia y el control de la polimerización de apertura de anillos de lactida.
- Investigar el uso de complejos de hierro (III) como iniciadores y catalizadores para la síntesis de PLA.
Principales métodos:
- La polimerización de apertura de anillo de lactida utilizando el dibenzoilmetano funcionalizado con hidroxilo (dbmOH) como iniciador.
- Utilizando hierro para formar Fe (dbmOH) 3 como un iniciador y catalizador metálico trifuncional.
- Investigando el hierro tris ((dbm) y el hierro tris ((acac) como catalizadores con dbmOH y alcohol bencílico como iniciadores.
Principales resultados:
- Fe ((dbmOH) 3 redujo significativamente los tiempos de polimerización a 10 minutos y mejoró el control del peso molecular en comparación con Sn ((oct) 2.2)
- Los polímeros centrados en el hierro (Fe ((dbmPLA) 3) se sintetizaron con índices de polidispersidad bajos (IDP < 1.1) incluso sin un catalizador de estaño.
- Los catalizadores de hierro se eliminaron efectivamente después de la polimerización a través del tratamiento con ácido, dando lugar al PLA desmetalizado para una mayor funcionalización.
Conclusiones:
- Los complejos de beta-diketonato de hierro (III) son iniciadores y catalizadores altamente efectivos para la rápida síntesis de PLA con un excelente control.
- Este enfoque ofrece una ruta versátil a los materiales PLA funcionales para aplicaciones de biomateriales y catalíticos.
- Los complejos de hierro proporcionan una alternativa reciclable y eficiente a los catalizadores tradicionales de estaño en la polimerización de lactida.
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