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Vitrímeros basados en ésteres de boro con estabilidad mejorada mediante coordinación interna de boro y nitrógeno
Xiaoting Zhang1, Shujuan Wang1, Zikang Jiang1
1School of Chemistry, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P. R. China.
Journal of the American Chemical Society
|December 17, 2020
Resumen
Los nuevos enlaces de diéster borónico cíclico de coordinación de nitrógeno (NCB) ofrecen una mejor resistencia al agua y al calor en los polímeros. Estas nuevas conexiones permiten la creación de vitrímeros sostenibles, autocurativos y reprocesables con una mayor estabilidad.
Área de la Ciencia:
- Química de los polímeros
- Ciencias de los materiales
- Química orgánica
Sus antecedentes:
- Los polímeros que contienen boro ofrecen propiedades únicas para aplicaciones avanzadas.
- Las especies de organoboron con enlaces B-O reversibles se utilizan en polímeros autocurables y reprocesables.
- Los ésteres borónicos y las boroxinas convencionales sufren de inestabilidad hidrolítica, lo que limita su uso.
Objetivo del estudio:
- Investigar la estabilidad hidrolítica y la química covalente dinámica de los enlaces de diéster borónico cíclico (NCB) coordinador de nitrógeno.
- Desarrollar una nueva clase de vidrificadores basados en enlaces de BCN con mayor estabilidad y reprocesamiento.
- Explorar el potencial de los vínculos entre los BCN para el diseño de materiales sostenibles de próxima generación.
Principales métodos:
- Síntesis de nuevos vitrímeros que incorporan enlaces NCB mediante reacciones de hidrógeno reactivo con isocyanato.
- Estudios termodinámicos y cinéticos para evaluar la estabilidad y las reacciones de intercambio de los enlaces de los BCN.
- Caracterización de los compuestos modelo (NCBC-X1, NCBC-X2) y de los vitrímeros de poliuretano/poliuretano resultantes.
Principales resultados:
- Los enlaces NCB demuestran una mayor resistencia al agua y al calor en comparación con los ésteres de boro convencionales.
- Los vitrímeros basados en enlaces NCB presentan una excelente resistencia a los solventes y propiedades mecánicas.
- La transesterificación de los enlaces NCB al calentarse permite la reparación, el reprocesamiento y el reciclaje de los materiales.
- La coordinación interna N → B en los enlaces de los BCN contribuye a mejorar la estabilidad hidrolítica y térmica.
Conclusiones:
- Los enlaces NCB representan una alternativa prometedora a los ésteres de boro convencionales para la creación de polímeros covalentes estables y dinámicos.
- Los vitrificadores desarrollados basados en NCB ofrecen una vía sostenible para el diseño de materiales con propiedades ajustables y ciclos de vida extendidos.
- Este trabajo proporciona una nueva estrategia para avanzar en el campo de los polímeros sostenibles a través de una mayor estabilidad hidrolítica y térmica.
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