Strongly toughened heat‐resistant cyanate ester resin‐based coatings doped by Tb³⁺‐complex anchored‐<scp>uCNTs</scp> with green fluorescent properties

Abstract Thermally stable polymeric coatings are widely used for metal protection at high temperatures, but their brittle weakness makes them unavailable to durable environment. To overcome that, we report properties of cyanate ester resin (CER) coating doped with unzipped carbon nanotubes (uCNTs) loaded with terbium complex (TBP) as nanofiller. The performance of the coating showed that the bending flexibility, adhesion, and impact resistance of the doped coatings was significantly improved. The cylinder bending test showed that the minimal bending diameter of CER doped with TBP‐uCNTs coating reached 6 mm without failure, which represents a significant improvement compared to the pure CER coating (18 mm). Surprisingly, the impact resistance reached the highest value of 50 cm without any failure of the coating. X‐ray diffraction, Fourier transform infrared spectroscopy, Raman, x‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy studies of CNTs, uCNTS, TBP‐uCNTs, and properties of CER indicate that formation of CER/TBP‐uCNTs composite is supported by a chemical reaction between hydroxyl groups of TBP‐uCNTs and the cyanate groups of CER resulting in fabrication of a solid cross‐linked structure. The thermal decomposition temperature of the coating increases from 409°C for pure CER to 453°C for CER/TBP‐uCNTs. The fluorescence spectra show that CER/TBP‐uCNTs exhibits strong luminescence at 550 nm.