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La polimerización de la metátesis de apertura de anillo de adición pulsada: síntesis catalizador-económicas de

John B Matson¹, Scott C Virgil, Robert H Grubbs

¹Center for Catalysis and Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.

Journal of the American Chemical Society

|February 14, 2009

Resumen

La polimerización de metátesis de apertura de anillo de adición pulsada (PA-ROMP) permite la síntesis controlada de polímeros y copolímeros de bloque con una distribución de peso molecular estrecha. Este nuevo método utiliza un agente de transferencia de cadena para regenerar el iniciador, lo que permite múltiples ciclos de polimerización a partir de un solo catalizador.

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.

Sus antecedentes:

La polimerización por metástasis de apertura de anillo (ROMP) es un método versátil para la síntesis de polímeros.
El ROMP tradicional puede sufrir limitaciones en el control preciso del peso molecular y la polidispersidad.
La transferencia controlada de la cadena y la regeneración del iniciador son desafíos clave en ROMP.

Objetivo del estudio:

Investigar y demostrar las capacidades de la polimerización de metátesis de apertura de anillo de adición pulsada (PA-ROMP).
Para preparar homopolímeros y bloquear copolímeros con pesos moleculares controlados y baja polidispersidad.
Optimizar el PA-ROMP para una regeneración eficiente del iniciador y múltiples ciclos de polimerización.

Principales métodos:

Síntesis de homopolímeros y copolímeros de poli (ester tert-butilo o imida del boreneno) utilizando PA-ROMP.
Utilizando un agente simétrico de transferencia de cadena cis-olefina (CTA) para el cierre simultáneo de la cadena y la regeneración del iniciador.
Empleando un catalizador de metátesis de rutenio de inicio rápido y un sistema robótico Symyx para un control preciso.
Caracterización de polímeros mediante cromatografía de permeación de gel con dispersión de luz láser multiángulo.

Principales resultados:

PA-ROMP produjo con éxito homopolímeros dispersos estrechamente y copolímeros de bloque.
Se lograron múltiples ciclos de polimerización (1-10) a partir de un solo iniciador de metal con pesos moleculares controlados.
Los copolímeros de bloque casi perfectos fueron sintetizados por adición secuencial de monómeros.
Se optimizó la duración de la etapa de recubrimiento final / iniciación-regeneración.

Conclusiones:

PA-ROMP ofrece alta fidelidad en el cierre de la cadena y la regeneración del iniciador.
Este método permite un control preciso de la arquitectura del polímero, el peso molecular y la polidispersidad.
PA-ROMP es una poderosa técnica para sintetizar polímeros bien definidos y copolímeros de bloque.

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