Programming of Hierarchical Noncovalent Interactions Enables Thermoplastic Elastomers With Ultrahigh Mechanical Strength and Dynamic Stability

ABSTRACT Noncovalent thermoplastic elastomers face a persistent trade‐off between stability and processability; strategies relying on increasing interaction density are reaching diminishing returns. Here, we report a hierarchical programming strategy for noncovalent interactions that moves beyond the parallel superposition of multiple weak bonds. Guided by multiscale simulations, we predict and design a thermoplastic elastomer in which strong naphthalene π–π stacking acts as primary directional anchors, templating the ordered assembly of a secondary hydrogen‐bond network through conformational confinement and producing a synergistic response larger than simple additivity. The linear polymer system achieves an ultrahigh tensile strength of 99.6 MPa and a stress‐relaxation activation energy of 153.5 kJ mol − 1 , comparable to values typically reported for covalent adaptable networks. Using computational chemical calculations and characterization, we clarify how the layered division of labor between interactions governs macroscopic stability. The resulting elastomers are reprocessable and tolerate harsh conditions, offering a generalizable design principle for noncovalent materials.