Stretchable, Ultralong Room‐Temperature Phosphorescence Poly(urethane‐urea) Elastomer Resistant to Humidity and Heat

Abstract Polymeric room‐temperature phosphorescence (RTP) materials exhibiting facile processability, high thermal stability, and environmental compatibility have garnered considerable attention. However, achieving excellent stretchability in simultaneity with ultralong RTP remains challenging because most RTP polymers rely on rigid structures with inherently poor tensile properties. Herein, a stretchable, ultralong RTP polyurethane is prepared through copolymerizing a novel phosphor dihydroxy‐functionalized indolocarbazole, 4,4′‐methylenedicyclohexyl diisocyanate (HMDI), poly(tetrahydrofuran) (PTMEG 2000), and adipic dihydrazide (AD). The phosphor is covalently bonded to the polyurethane backbone, which facilitates the stabilization of triplet excitons and achieves ultralong RTP. The obtained copolymers exhibit a maximum strain of 1400% and the longest phosphorescence lifetime of 1888 ms. Additionally, the polyurethanes exhibiting different afterglow colors are prepared by varying the molecular structure of the phosphor. Notably, the RTP polyurethane materials also display resistance to humidity and heat. This work may provide a new option for the development of stretchable, ultralong RTP materials.