Spider-silk-inspired dynamic poly(urethane-urea) networks with mechanical reinforcement via mismatched supramolecular interactions for luminescent fibers

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.