Effects of Triazole Functionalized SiO2/TiO2 Nanoparticles in Polyurethane Coating: A Study on Structural, Thermal, Dynamic Mechanical, Morphological and Electrochemical Properties in Marine Environment

Abstract

AbstractNewly synthesized functional nanoparticles, 3‐amino‐1, 2, 4‐triazole‐5‐thiol (ATAT)/SiO2−TiO2 nanoparticles, investigated by Transmission electron microscopy (TEM), Scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM/EDX), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) analysis, were added to the polyurethane (PU) matrix. The produced PU‐ATAT/SiO2−TiO2 nanocomposite coated steel specimen was studied by Scanning electrochemical microscopy (SECM), potentiodynamic polarization and Electrochemical impedance spectroscopy (EIS) for their barrier properties against corrosion. The coating resistance (Rcoat) of the PU‐ATAT/SiO2−TiO2 nanocomposite was found to be 2956.90 kΩ.cm2. It was found that the coating resistance of PU‐ATAT/SiO2−TiO2 nanocomposite coating was over 50 % higher than that of the PU coating. The current measured along the scratched surface of the PU‐ATAT/SiO2−TiO2 nanocomposite coating was found to be very less (1.65 nA). The degradation products analyzed by SEM/EDX and XRD displayed the enriched ATAT/SiO2−TiO2 nanoparticles which hindered the passage of electrolytes into the interface of coating. The hydrophobic nature of the PU‐ATAT/SiO2−TiO2 nanocomposite coating (θ=115.4°) was confirmed by water contact angle measurement. The least oxygen permeability was observed in the PU‐ATAT/SiO2−TiO2. The improved mechanical properties were found by dynamic mechanical analysis (DMA) for the PU‐ATAT/SiO2−TiO2 nanocomposite coating. Therefore, the newly synthesized PU‐ATAT/SiO2−TiO2 nanocomposite provided an outstanding barrier and mechanical properties due to the addition of ATAT/SiO2−TiO2 nanoparticles to the polyurethane, which obstructed the degradation of materials and assisted in prolonging the life of the coated steel.