6533b7d8fe1ef96bd126acc3

RESEARCH PRODUCT

Self-Diffusion of Associating Star-Shaped Polymers

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The dynamics of associating bonds in transient polymer networks exerts a paramount influence on their relaxation and time-dependent mechanical properties. In particular, diffusive motion of polymers mediated by the dissociation and association equilibrium of reversible junctions can affect the materials’ structural stability, dynamic mechanical properties, and a broad spectrum of functionality that arises from the constant motion of polymer chains. In this work, forced Rayleigh scattering is used to measure the diffusion of terpyridine end-functionalized four-arm poly(ethylene glycol) polymers transiently interlinked by zinc ions in organic solvent across a wide range of length and time scales. Phenomenological superdiffusion, where the scaling of the squared length dimension vs time has a power-law exponent larger than one, is demonstrated as an intrinsic feature of these networks due to the interplay of chain dissociation and diffusion. Outside the superdiffusive regime, normal Fickian diffusion is reco...