Ultralong Room‐Temperature Phosphorescence Polymers with Superior Toughness and Stability via Hierarchical Hydrogen Bonding and Covalent Crosslinking

ABSTRACT Stretchable room‐temperature phosphorescent (RTP) materials hold broad application prospects in the field of flexible information encryption. However, the development of RTP materials that simultaneously exhibit long‐lived luminescence, excellent mechanical properties, and high stability remains challenging. Herein, we successfully fabricated a high‐performance stretchable RTP polymer by constructing a multiphase system featuring synergistic hierarchical hydrogen bonds and covalent crosslinks. The polymer achieves efficient synergy between optical and mechanical properties, demonstrating a phosphorescence lifetime of 3.42 s, a tensile strength of 59.3 MPa, and an exceptional toughness of 378.1 MJ m −3 . Moreover, it exhibits excellent luminescence stability in acidic, alkaline, and hot aqueous environments, as well as under an extreme strain of 1400%. Benefiting from its dense dual‐crosslinked network, the polymer undergoes only slight swelling in various organic solvents, and its optical and mechanical properties recover completely upon solvent evaporation. This work provides a novel strategy for the development of ultralong RTP materials with excellent toughness and high stability.