Improved design, analysis, preparation and properties of photothermal phase-change polyurethane materials based on zinc ion coordination

To form an intrinsic photothermal, high-strength and recyclability coating, a series of photothermal phase-change polyurethane materials which incorporates metal ions as coordination bonds was designed by polyethylene glycols of different molecular weights (6000, 8000, 10,000), diphenylmethane-4,4′-diisocyanate (MDI), zinc acetate, 1,5-naphthalenediol, p-benzoquinone dioxime, and triethanolamine (TEA). The photothermal phase-change polyurethane samples which synthesized with p-benzoquinone dioxime and 1,5-naphthalenediol as chain extenders, were named PUP-B (Li et al., 2024; Shi et al., 2021; Zhao et al., 2024 (6, 8, 10)) and PUP-N (Li et al., 2024; Shi et al., 2021; Zhao et al., 2024 (6, 8, 10)), respectively. To investigate their recyclability, these samples were dissolved and coated onto glass slides to obtain new polyurethane samples. After lighting for 420 s, the temperature of samples remained around 35–45 °C for approximately 5 min during cooling cycles, indicating excellent photothermal energy storage performance. The average maximum stress of PUP-B (10) and PUP-N (10) was 14.25 MPa and 11.96 MPa, respectively, while the average strain was 637 % and 486.44 %, demonstrating good tensile properties of the polyurethane material with PEG10K as the soft segments. The maximum water contact angle of the samples was 142.78°, indicating good hydrophobicity of the prepared samples. The recyclability, hydrophobicity, and photothermal energy storage capabilities of these materials make them suitable as green coating materials, providing new ideas for the development of aircraft anti-icing solutions.