Tuning the Dynamic Properties of Epoxy Vitrimers via Bioinspired Polymer-Nanoparticle Bond Dynamics

In this work, Fe₃O₄ nanoparticles anchored with dopamine molecules were developed via bioinspired iron-catechol coordination interactions, and the dopamine-modified Fe₃O₄ surface was linked to the matrix through strong interfacial interactions between the nanoparticles and the epoxy vitrimer. Results showed that the typical dynamic parameters of vitrimer could be readily adjusted in the epoxy vitrimer composites. These findings demonstrate that it is efficient to adjust the dynamic properties of vitrimers by introducing the metal-coordination bonds into epoxy vitrimer networks. The synergy of metal-catechol coordination and transesterification enriched the mechanism of dynamic regulation. In addition, the epoxy vitrimer composites were responsive to temperature and near-infrared light. The scratch could be successfully healed with 1 min on the surface of vitrimer composites under NIR irradiation even for the 1% addition of Fe₃O₄ nanoparticles. This approach shows potential to be generally applicable to different types of metal-coordination systems.