Design of Sustainable and High Strength-Toughness Thermoplastic Elastomer via a Strong Hydrogen Bond-Reinforced Nanostructure

Achieving sustainable and high strength-toughness thermoplastic elastomers remains a great challenge due to the inherent conflict of molecular design for high strength-toughness and sustainability during and after service life. Inspired by the microstructure of mussel byssus, we designed hydrogen bond-reinforced thermoplastic polyurethane-urea (HTPU) elastomers featuring phase-separated nanostructures along with a strong hydrogen bond-reinforced hard nanophase with an interphase distance of ∼ 5 nm, enabling maximum tensile strength of 79 MPa, toughness of 365 MJ m–3, stretchability of 1475%, and strength recovery of ∼ 100% for the optimized HTPU-P1 via a strong hydrogen bond-reinforced nanostructure. The mechanical properties are directly dominated by the tunable hydrogen bonds in the hard nanophase that leads to tunable strain-hardening behavior. Further designing a dynamic disulfide bond-contained hard nanophase and polycaprolactone diol (PCLD)-containing continuous phase endows HTPU-P6 with sustainability during and after service life. They include self-healing properties with up to 98.3% tensile strength recovery and 96.6% toughness recovery and cytotoxicity test-verified biocompatibility during service life as well as controlled degradation and subsequent upcycling after service life. Therefore, sustainability during service life can prolong service life and expand the biobased potential application, while sustainability after service life reduces the adverse impact on the environment and enhances subsequent value, highlighting the important value of sustainability during and after service life.