Functional Carbon Nanotubes Reinforced Epoxy Vitrimer Nanocomposites for Recyclable Strain Sensors

ABSTRACT Nanocomposites based on epoxy vitrimer offer a facile preparation process and recyclability, making them attractive for use in strain sensors. However, current research in this area often prioritizes the construction of conductive nanomaterial layers over a fundamental understanding of their integration into the vitrimer matrices. Here, amino‐functionalized multi‐walled carbon nanotubes (MWCNTs‐NH ₂ ) are incorporated into transesterification reactions (TERs)‐based epoxy vitrimers to develop conductive vitrimer (CV) nanocomposites. Due to the rigid structure and steric hindrance of MWCNTs‐NH ₂ , the stress relaxation time is longer from 445 to 861 s with the addition of MWCNTs‐NH ₂ from 3 to 5 wt%. Nevertheless, topological network rearrangements through TERs remained active, as evidenced by a comparable activation energy (121 kJ mol ⁻¹ ) to that of conventional TERs‐based vitrimers. The resulting CV nanocomposites allow for fragment recycling and chemical degradation in ethylene glycol, achieving a carbon nanotube recovery efficiency of 69%. Notably, these composites exhibit a non‐monotonic yet highly reproducible electrical response under strain, enabling their application in real‐time human motion monitoring. This work elucidates the role of functional nanomaterials in modulating vitrimer networks, thereby paving the way for fabricating reprocessable nanocomposites with precise strain sensing capabilities.