Mechanically-robust and humidity-tunable self-destructive polymers enabled by hydrogen-bond nanoconfinement.

Conventional materials typically maintain a stable solid state under specific application conditions. However, materials that combine high mechanical strength with reversible switching states are highly desirable for advanced technologies. Here, we present hydrogen-bond nanoconfined self-destructive polymers (HNSPs) that have robust mechanics and reversible solid-fluid switching capability at 25 °C. Upon exposure to moisture, HNSPs spontaneously transition from solid to fluid, with humidity-tunable switching rates. HNSPs with weight ratios (Rm) of 1.7 is 1.69 times higher self-destructive rate than those with Rm of 2.1, and at 90% relative humidity (RH), Rm=2.0 samples exhibit an 804.27% higher self-destructive efficiency than at 60% RH. Heating can reverse the fluid back to a solid, enabling reversible, humidity-programmable behavior. Mechanistically, large ordered hydrogen-bond clusters, reduced chain entanglement, and abundant hydrophilic groups collectively facilitate switching. This work provides a simple yet versatile strategy for designing robust, switchable self-destructive polymers, broadening their potential in next-generation devices.