Corrosion protection behavior of poly(N-methylpyrrole)/boron nitride composite film on aluminum-1050

Abstract

In this study, the surface of aluminum-1050 (Al-1050), which has industrial importance, was covered with poly(N-methylpyrrole)/boron nitride (PNMPy/BN) composite film in a mixture electrolyte of oxalic acid (OXA) and dodecylbenzene sulfonic acid (DBSA) by the galvanostatic method. Fourier Transform Infrared (FT-IR) Spectroscopy, Thermogravimetry (TG), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) techniques were used for the characterization and morphology of the film. Corrosion analyzes were performed with Tafel polarization and electrochemical impedance spectroscopy (EIS) in 0.1 M H2SO4. The DBSA-OXA mixing electrolyte markedly increased the homogeneity and adhesiveness of the coatings. The corrosion efficiency of PNMPy/BN composite film coated on the Al-1050 surface was 98.6%. BN nanoparticles significantly reduced the size of agglomerate structures on the surface of the polymer film, while reducing the average thickness of the polymer film from 28 μm to 20 μm. Besides, the filling process reduced the surface roughness of PNMPy from 121 to 95 nm. EIS analyzes showed that PNMPy and PNMPy/BN composite films increased the charge transfer resistance (Rct) of Al-1050 around 172 and 238 times, respectively. It was observed that coatings in the corrosive environment did not separate from the Al-1050 surface even at the end of the 6th day, and the PNMPy/BN composite film provided the best protection.