Entropy-driven balance between high strength and effective damping capability of composite elastomers with wide service temperature range

The development of composite elastomers that simultaneously achieve high strength and effective damping remains a formidable challenge. Inspired by the hierarchical and multiphase architecture of human skin, we designed a polyurethane-based composite elastomer through an interfacial entropy regulation strategy enabled by a multifunctional nanofiller. Specifically, a rigid small-molecule filler (TTP, 1 wt%) is introduced into the polyurethane matrix, creating a dense and dynamic interphase between the soft and hard domains. This nanofiller-induced interfacial engineering significantly enhances the material's conformational entropy—analogous to the regulatory interface in the extracellular matrix of skin. The nano-confined, disordered TTP network establishes a low-entropy-penalty reinforcement mechanism, providing substantial strength and toughness without markedly restricting chain mobility, thereby overcoming the classic trade-off between ordered reinforcement and segmental dynamics in composite systems. The resulting composite elastomer achieves unprecedented comprehensive performance, including ultrahigh tensile strength (48.4 MPa), exceptional toughness (105.8 MJ m⁻³), and outstanding damping (tan δ > 0.3) over an exceptionally broad temperature (−1.8 °C to 140 °C) and frequency (10⁻⁷–10³ Hz) range. Furthermore, the composite exhibits excellent sustainability, featuring closed-loop recyclability triggered by the green, low-toxicity solvent ethanol with minimal property loss—an environmentally friendly pathway for high-performance composite elastomers. Overall, this work establishes a new paradigm for designing robust, damping, and recyclable materials through nanofiller-mediated interface engineering, with broad application prospects in composite-based engineering systems requiring integrated mechanical and functional performance.