High efficient corrosion inhibitor of water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites for 316 L stainless steel

다국어 초록 (Multilingual Abstract)

In this work, new water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites (PPy–SMF NCs) were first synthesized by one‐step in‐situ polymerization of pyrrole with FeCl3 in the presence of various mole ratios of sulfonated melamine formaldehyde (SMF). The characterization of the PPy–SMF NCs was investigated via ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray, dynamic light scattering, transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, and conductivity measurements. The resulting PPy–SMF NCs were proved to improve the solubility, electrical properties, and thermal stability. The anti‐corrosion performance of PPy‐SMF NCs on 316 L stainless steel (316 L SS) was examined using electrochemical impedance spectroscopy, potentiodynamic polarization, and weight‐loss method. The result showed that the PPy–SMF NCs acts as a mixed‐type inhibitor, as well as a protective layer to 316 L SS against corrosion in 3.5% NaCl solution. The Langmuir adsorption isotherm was well fitted and suitable to explain the adsorption behavior of the PPy‐SMF NCs on 316 L SS surface. The inhibition efficiency of PPy‐SMF NCs is 99% by the weight‐loss method which could be attributed to the protective layer formed on 316 L SS surface by the adsorption of PPy‐SMF NCs.