Abstract: Most current soft and flexible luminescent matrices exhibit poor mechanical performance, leading to limited performance reliability and longevity. Inspired by the heterogeneous structure of spider silk, we developed a sacrificial, robust, and self-healing poly(urethane-urea) (Supra-PU) elastomer with a physically hydrogen-bonded crosslinked network via the mismatched mechanistic interplay between flexible and rigid segments. This engineered structure leads to denser hard domains and effective energy dissipation, enabling the optimal Supra-PU elastomer to exhibit extraordinary mechanical properties, such as an ultrahigh strength of 30.6 MPa with a fracture strain of 1251.8 %, a true stress at break of 423.3 MPa, toughness of 102.9 MJ m^-3, and damage-tolerant performance with a high fracture energy of 4.7 kJ m^-2. Moreover, loosely packed and noncrystallized hard domains impart the desired network with low chain restriction and high relaxation dynamics, resulting in a high healing efficiency of 92.1 % with restored toughness of 94.8 MJ m^-3. Furthermore, luminescent fibers are achieved via wet spinning with superior mechanical properties and cyan afterglow (~0.8 s). This meticulous molecular engineering provides valuable insights for advancing high-performance self-healable poly(urethane-urea) and luminescent materials.

Key words: Self-healing, Mismatched supramolecular interactions, Poly(urethane-urea), Wet spinning, Luminescent fiber