腰果酚基聚氨酯疏水自修复涂层的制备及防腐性能研究OA北大核心

Cardanol-based benzoxazine(CPBOZ)with a polyol structure was synthesized from cashew phenol by click and Mannich reactions,and a series of cardanol-based polyurethanes(CPBPUs)were subsequently prepared by varying the molar ratio of CPBOZ and bis(2-aminophenyl)disulfide(DTDA).The structures of the products were characterized using Fourier-transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance(1H NMR),and the thermal properties,hydrophobicity,film properties,self-healing performance,and corrosion resistance of the cured CPBPU coatings were analyzed.When n(—OH)∶n(—NH2)was 0.4∶0.6,the CPBPU-4 coating exhibited excellent thermal stability and solvent resistance,and the best self-healing effect,with a gel content of 89.10％,a water contact angle(WCA)of(98.1±2.2)°,a pencil hardness of 5H,an adhesion rating of 5,and a flexibility of 2 mm.In electrochemical impedance spectroscopy(EIS)tests,the impedance modulus(|Z|0 01 Hz)of the CPBPU-4 coating was 5.1 × 108 Ω·cm2 at low frequency,demonstrating good corrosion protection.After scratching,the|Z|0 01 Hz of the coating dropped to 1.9 × 104 Ω·cm2,but it recovered to 1.4 × 105 Ω·cm2 after self-healing.Neutral salt spray tests further confirmed the excellent corrosion resistance of the CPBPU-4 coating,as it withstood 7 days in a salt spray environment.