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El colapso de las cadenas libres de polímeros en una red
Science (New York, N.Y.)
|April 21, 1995
Resumen
Las cadenas de polímeros lineales en una matriz reticulada adoptan diferentes conformaciones. Su tamaño depende de la longitud de la cadena en relación con la red.
Área de la Ciencia:
- Ciencia de los polímeros y ciencia de los materiales.
Sus antecedentes:
- Comprender el comportamiento de la cadena polimérica dentro de matrices complejas es crucial para el diseño de materiales.
- Los cambios conformacionales de los polímeros lineales confinados en redes entrelazadas no se comprenden completamente.
Objetivo del estudio:
- Para investigar la conformación de las cadenas de polímeros lineales confinadas dentro de una matriz de polímeros reticulados.
- Para determinar cómo la longitud de la cadena y el tamaño de la malla de la red influyen en la conformación del polímero.
Principales métodos:
- Se empleó la dispersión de neutrones para medir la conformación de las cadenas de polímeros lineales.
- El estudio varió la longitud de las cadenas lineales (Nl) en relación con el tamaño de malla de la red interconectada (Nc).
Principales resultados:
- Se observaron tres regímenes conformacionales distintos basados en la relación entre Nl y Nc).
- Cuando N (c) > Nl, el radio de rotación (R (g)) de las cadenas lineales coincidía con el de los fundidos no cruzados.
- Cuando N (c) < Nl, R (g) disminuyó, siguiendo una relación de escala predicha para cadenas en campos de obstáculos aleatorios.
- En N ((c) << Nl, las cadenas lineales exhibieron segregación.
Conclusiones:
- La conformación de las cadenas de polímeros lineales en matrices entrelazadas es altamente dependiente de la longitud relativa de la cadena y el tamaño de la malla de la red.
- La dispersión de neutrones revela regímenes distintos de comportamiento de la cadena, incluida la contracción y la segregación, bajo confinamiento.
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