Designing all-vitrimer nanocomposites to combine low energy consumption, mechanical robust and recyclability

Advances in vitrimer nanocomposites are unlocking new pathways for engineering elastomers with integrated mechanical robustness, low energy dissipation, and recyclability. Here, we report an all-vitrimer nanocomposite (DNP/VNC) reinforced with reconfigurable dynamic nanoparticles (DNPs), investigated through coarse-grained molecular dynamics simulations. Dynamic covalent bonds (DCBs) are strategically embedded within the DNPs, the filler-matrix interface, and the matrix, constructing a hierarchically dynamic polymer network. Compared to conventional rigid nanoparticle systems (RNP/VNCs), DNP/VNCs exhibit markedly improved filler dispersion, interfacial compatibility, and dynamic reversibility, owing to the flexible and reactive nature of DNPs. Under mechanical deformation, the DNPs actively participate in stress transfer, promote matrix chain orientation, and enable interfacial bond reconfiguration, leading to enhanced tensile strength, triaxial toughness, and network adaptability. Notably, DNP/VNCs demonstrate exceptional self-healing capabilities and mechanical recovery, preserving over 90 % healing efficiency even after ten damage-healing cycles without requiring external triggers. In addition, the synergistic interaction between the deformable nanofillers and the dynamic vitrimer network leads to significantly reduced hysteresis loss and improved energy dissipation during repeated tensile and shear loadings. This work reveals the molecular-level mechanisms of the structure-property relationships in all-vitrimer nanocomposites, providing valuable insights and rational design principles for the development of next-generation high-performance and sustainable vitrimer nanocomposites.