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Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
La polimerización selectiva de carbodiimidas en sentido helicoidal: la construcción de polímeros permanentemente
Gonglu Tian1, Yujie Lu, Bruce M Novak
1Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA.
Journal of the American Chemical Society
|April 1, 2004
Resumen
Los catalizadores homoquirales permiten la polimerización selectiva con sentido de hélice de los monómeros achirales. Los polímeros con grupos fenilo específicos exhiben una actividad óptica estable, lo que demuestra el control sobre la estructura y las propiedades del polímero.
Área de la Ciencia:
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- La catálisis es la catálisis.
- La estereoquímica es la estereoquímica.
Sus antecedentes:
- Investigando la polimerización selectiva con sentido de hélice de los monómeros achirales utilizando catalizadores homoquirales.
- Comprender el control de la polimerización (cinético frente a termodinámico) a través de estudios de mutación de los polímeros quirales de carbodiimida.
Objetivo del estudio:
- Para explorar la polimerización de carbodiimidas aquirales utilizando un catalizador homoquiral específico, (S-BINOL) Ti (OiPr) 2.
- Para evaluar la inducción asimétrica y la estabilidad térmica de los polímeros resultantes.
Principales métodos:
- La polimerización de varios monómeros de carbodiimida aciral utilizando el (S-BINOL) Ti ((OiPr) 2.
- Análisis de las propiedades del polímero, incluido el rendimiento, la inducción asimétrica y el comportamiento de racemización al calentarse.
- Caracterización de películas delgadas de poli-7 para propiedades ópticas.
Principales resultados:
- Los carbodiimidos achirales se polimerizaron con buenos rendimientos (86-95%) y diversos grados de inducción asimétrica.
- Polímeros derivados de monómeros con grupos fenólicos simétricos (poli-3, -4, -5) racemizados después del calentamiento.
- Los polímeros con grupos fenólicos no simétricos (poli-6, poli-7) produjeron polímeros ópticamente activos resistentes a la racemización.
- Las películas delgadas de poli-7 exhibieron una alta opalescencia.
Conclusiones:
- El estudio demuestra una exitosa polimerización selectiva de sentido hélice de los carbodiimidas achirales.
- La presencia de grupos fenólicos no simétricos específicos en el monómero dicta la formación de polímeros ópticamente estables.
- Este enfoque ofrece control sobre la estereoquímica y las propiedades del polímero, con aplicaciones potenciales sugeridas por la naturaleza opalescente de las películas de poli-7.
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