Reprogramming Multi‐Dimensional Material Properties of Cured Thermosets by Hot‐Pressing

Thermosets, characterized by their permanently crosslinked polymer network, are pervasive and indispensable in modern industry and our daily lives. However, once cured, their network structures and material properties are generally fixed, limiting further adaptation to users' evolving functional requirements and often leading to premature replacement even without property deterioration. Herein, by exploiting the widely used reversible aza‐Michael reaction, we developed a reprogramming strategy that enables controlled dissociation and reconfiguration of cured networks, thereby allowing programmable modulation of multi‐dimensional material properties (mechanical, electrical, optical, acoustic, etc.) via hot‐pressing (e.g., 1700% variation in Young's modulus, 300% increase in dielectric constant, 1280% enhancement in actuation sensitivity). Moreover, this platform offers effective solutions to longstanding challenges in materials science: for instance, we access extraordinary impact‐resistant materials with ultrahigh‐speed impact absorption (∼380 MJ/m 3 at 8000 s −1 ), far exceeding the literature values of elastomers or their composites. Unlike conventional recycling strategies aiming to recover original material properties, our work highlights a general platform to redefine thermoset functionality after curing, paving the way for on‐demand customization and reutilization of high‐performance thermosets.