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Updated: Mar 25, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Conversión topológica lineal y cíclica reversible por luz y calor de polímeros telecélicos con grupos finales de

Takuya Yamamoto^1,2, Sakyo Yagyu¹, Yasuyuki Tezuka¹

¹Department of Organic and Polymeric Materials, Tokyo Institute of Technology , O-okayama, Meguro-ku, Tokyo 152-8552, Japan.

Journal of the American Chemical Society

|February 27, 2016

Resumen

Este estudio muestra la conversión reversible de la topología del polímero utilizando luz o calor. Los polímeros pueden cambiar entre formas lineales y cíclicas, con una conversión más rápida para pesos moleculares más bajos.

Área de la Ciencia:

Química de los polímeros
Ciencias de los materiales
Química supramolecular

Sus antecedentes:

El control de la topología del polímero es crucial para las propiedades avanzadas del material.
El desarrollo de polímeros sensibles a los estímulos permite el diseño de materiales dinámicos.
Las reacciones fotoquímicas ofrecen un control preciso sobre las transformaciones del polímero.

Objetivo del estudio:

Investigar la conversión topológica lineal-cíclica reversible de los polímeros.
Explorar la influencia del peso molecular y la química del grupo final en esta conversión.
Para demostrar que la luz y el calor desencadenan cambios topológicos.

Principales métodos:

Síntesis de polímeros telecélicos con grupos finales antril o cumarinil.
Las reacciones fotoquímicas (irradiación UV a 365 nm y 254 nm) para inducir la ciclización y la linearización.
Tratamiento térmico (150 °C) para devolver los polímeros cíclicos a su forma lineal.
Caracterización mediante resonancia magnética nuclear (RMN), cromatografía de exclusión de tamaño (SEC) y espectrometría de masa de tiempo de vuelo por desorción láser asistida por matriz / ionización (MALDI-TOF MS).

Principales resultados:

Se han sintetizado con éxito poli (óxido de etileno) y poli (tetrahidrofuranos) telecélicos con grupos finales de ántrilo.
Se ha demostrado la eficiencia de la ciclización inducida por la luz de polímeros terminados en antirilo (Ant-CO2-PEO) tanto en medios acuosos como orgánicos.
Se muestra la reversión térmica cuantitativa de los polímeros cíclicos a su estado lineal, confirmando la repetibilidad.
Se observó ciclización dependiente del disolvente para polímeros terminados en cumarinyl (Cou-PEO), destacando el papel de las interacciones hidrofóbicas.

Conclusiones:

La conversión topológica lineal-cíclica reversible es alcanzable tanto en polímeros hidrófilos como hidrófobos.
La eficiencia de la ciclización depende del peso molecular del polímero, la química del grupo final y el entorno del disolvente.
La luz y el calor sirven como disparadores efectivos para la conmutación topológica reversible, abriendo vías para sistemas dinámicos de polímeros.

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