Synthesis, characterization and corrosion performance of polyaniline-montmorillonite clay nanocomposites

In-situ polymerization was used to synthesize a novel nanocomposite material based on layered silicate clay and intrinsically conducting polymers (ICPs): polyaniline (PANi). Conducting polymers including PANi and PPy are known to effectively protect active metals against corrosion. Montmorillonite (MMT) clay was successfully incorporated into polyaniline to form PANi-clay (PACN) nanocomposites with improved properties. The relationship between the synthesis conditions and the structure, thermal behavior and oxidation states of the PANi-clay nanocomposites were determined and a further insight into the processing, structure and property correlations was gained.; The effect of processing parameters such as oxidant and filler concentration on the structure and properties of the nanocomposites were studied by using Fourier transform infrared spectroscopy (FTIR) and wide angle X-ray scattering (WAXS) together with thermal analysis. It was shown that the oxidant concentration plays an important role in controlling the properties and the structure of the PACN. It was shown that the degradation temperature of PACN decreases with the increasing concentration of oxidant. In depth study was done by FTIR to determine the molecular structure and the oxidation state of PANi in the composites. The morphology of the nanocomposites was observed by using the scanning electron microscopy (SEM). Transmission electron microscopy (TEM), wide-angle X-ray scattering and small angle X-ray scattering (SAXS) study showed the presence of both intercalated and exfoliated clay in the polymer matrix. X-ray diffraction analysis provides additional structural information on both PANi and PACN nanocomposites synthesized at different processing conditions.; The nanocomposites were combined with epoxy and formulated into coatings for use in the protection of AA 2024-T3. The effect of PACN nanocomposites on the curing of epoxy resin was studied by using FTIR and a significant enhancement in the degree of curing of epoxy was observed. Corrosion performance of the nanocomposite-epoxy coatings on AA 2024 alloy was determined by using scanning vibrating electrode technique (SVET).