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Determinación de las constantes de equilibrio para la polimerización radical por transferencia atómica
Wei Tang1, Nicolay V Tsarevsky, Krzysztof Matyjaszewski
1Center for Macromolecular Engineering, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA.
Journal of the American Chemical Society
|February 2, 2006
Resumen
Fischer modificado modificado
Área de la Ciencia:
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- Química Física es la química física.
- Química orgánica es la química orgánica.
Sus antecedentes:
- La polimerización radical por transferencia atómica (ATRP) se basa en el equilibrio entre las especies activas y latentes.
- La determinación precisa de las constantes de equilibrio ATRP (K ((ATRP)) es crucial para controlar la polimerización.
- Los métodos existentes que utilizan las ecuaciones de Fischer se limitan a conversiones bajas y valores de K ((ATRP).
Objetivo del estudio:
- Desarrollar y validar las ecuaciones modificadas de Fischer para determinar K ((ATRP) a conversiones más altas.
- Para medir con precisión K ((ATRP) para varios catalizadores y halogenuros de alquilo.
- Para investigar las relaciones estructura-reactividad en ATRP.
Principales métodos:
- Ecuaciones de Fischer modificadas que incorporan cambios en las concentraciones de catalizador e iniciador.
- Simulaciones cinéticas para validar las nuevas ecuaciones.
- Espectrometría UV-vis para monitorear las especies de cobre (X-Cu(II)).
- Cromatografía de gases (GC) para hacer un seguimiento de la concentración del iniciador.
Principales resultados:
- Las ecuaciones modificadas determinan con precisión K (((ATRP) en conversiones >10% y K (((ATRP) >10 ((-7).
- Se han determinado con éxito los valores de K (ATRP) para varios sistemas de catalizadores/alquilo haluros.
- Demostró el efecto de las variaciones estructurales en la reactividad de los componentes ATRP.
Conclusiones:
- Las ecuaciones modificadas de Fischer amplían la aplicabilidad de la determinación de la constante de equilibrio en ATRP.
- Los valores precisos de K ((ATRP) son esenciales para el control preciso de los procesos de polimerización.
- Comprender las relaciones estructura-reactividad ayuda en el diseño de sistemas ATRP eficientes.
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