Tough, Creep-Resistant, and Recyclable Polyurea Elastomers via Hierarchical Dynamic Networks with Load-Bearing Electromagnetic Shielding Capability

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Simultaneously achieving toughness, creep resistance, and recyclability in polyurea elastomers remains challenging since hydrogen-bond-dominated networks readily undergo thermally induced topological relaxation. Herein, hierarchical dynamic polyurea elastomers were developed by synergistically integrating multiple hydrogen bonds and metal–ligand coordination interactions. In this work, adipic dihydrazide (ADH) was introduced to establish dense hydrogen-bonding domains for efficient energy dissipation, while 2,6-diaminopyridine (DAP) and metal ions (Zn2+, Co2+, and Ca2+) were employed to construct dynamic coordination cross-linking sites for network stabilization. Metal coordination significantly promoted hard-domain aggregation and coordination-enhanced microphase stabilization, thereby improving high-temperature creep resistance. The Ca2+-coordinated elastomer achieved a balance between dynamic rearrangement and topological stabilization, exhibiting a tensile strength of 29.2 MPa, a toughness of 128.24 MJ/m3, and excellent creep resistance at elevated temperatures. Meanwhile, the reversible hierarchical network enabled efficient thermal and solvent-assisted recyclability through supramolecular reconstruction. Furthermore, laminated graphene film/polyurea composites achieved load-bearing electromagnetic shielding with an average shielding effectiveness of 77.29 dB in the X-band. This work provides an effective strategy for designing multifunctional dynamic elastomers with integrated mechanical robustness, high-temperature creep-resistance, recyclability, and electromagnetic shielding capability.