Multilayered nanocomposite coatings for enhanced anticorrosive, flame retardant, and mechanical properties in automobile and aerospace industries

Abstract

AbstractThe anticorrosion, flame retardant, and mechanical properties of polyurethane (PU) coatings have been improved by the integration of nickel disulfide (NiS2), 2,5‐Bis(4‐aminophenyl)‐1,3,4‐oxadiazole (BAO), and graphene oxide (GO). The structural, morphological, dielectric, and hydrophobic behaviors of the films were characterized for the different formulations of coatings such as pure PU, PU‐NiS2, PU‐BAO/NiS2, PU‐GO/NiS2, and PU‐GO/BAO‐NiS2 (nanocomposite) by means of scanning electron microscope/X‐ray energy dispersive spectroscopy, transmission electron microscope, thermogravimetric analysis, X‐ray photoelectron spectroscopy, X‐ray diffraction, and contact angle measurement. As a result, with the addition of only 0.3% GO/BAO‐NiS2, the dielectric constant of PU was increased by 81‐fold at 1 Hz. Additionally, the nanocomposite had significantly lower peak heat release rate and overall heat released values than pure PU, a difference of 57% and 51%, respectively, demonstrating its greater flame retardancy. The electrochemical techniques and mechanical testing confirmed that GO/BAO‐NiS2 (0.3%) composite exhibit enhanced anticorrosive, hydrophobic, flame retardancy, and mechanical performance of the PU coating. The super hydrophobic behavior is confirmed by its water contact angle of 165°. Furthermore, the resistance of the nanocomposite was found to be much higher (16,985.6 kΩ.cm2) than that of the pure PU (145.4 kΩ.cm2) and the microhardness and tensile strength were increased sharply. Therefore, the nanocomposite could act as a potential coating material for industrial applications.