Rheological Evidence of Reversible Host–Guest Complex Formation in Polymers

Le résumé fourni par la source

Understanding how reversible interactions influence polymer dynamics is essential for designing advanced functional materials. Host–guest complexes represent a versatile class of reversible interactions owing to their molecular selectivity and tunable bonding strength. Although host–guest complexes have been widely utilized as reversible cross-links in aqueous polymer systems, their role in bulk polymers remains unclear, mainly because direct experimental observation of complex formation in the solid state is challenging. This study addresses whether host–guest complexes can function as effective reversible cross-links in polymers and how they influence chain dynamics. Herein, polymers incorporating host–guest complexes exhibited characteristic changes in linear viscoelasticity that are quantitatively described by the sticky reptation model. The plateau modulus (GN) gradually decreased, while the terminal relaxation time (τd) increased with increasing host–guest content. The GN values are well explained by considering both entanglement dilution and reinforcement by reversible cross-links. The prolonged τd indicates suppressed chain reptation due to reversible topological constraints. Furthermore, the effective association probability (p) and bonding lifetime (τs) were extracted through model-based analysis, providing indirect yet quantitative evidence of reversible complex formation in polymers. These findings establish rheological analysis for probing supramolecular interactions in polymers and highlight host–guest complexes as tunable modifiers of polymer dynamics.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.