Rheological, EMI and corrosion properties of epoxy coating with nanoparticle and conductive carbon black

Abstract

The purpose of this paper was determining the effects of two nanoparticles additions in a commercial epoxy coating system on rheology characterization. Two kinds of hybrid organic–inorganic silicates (benzytallowdimethylammonium salts with bentonite) were studied, APA, with C14-16 organic chain and, HT, with C2-4 organic chain. A 22 factorial design, with two categorical nanoparticules factors was applied. The experimental data of viscosity were fit to three different rheological constitutive models: Herschell-Bulkley, Carreau-Yasuda and Cross. The best fit was obtained by Herschel-Bulkley model. The APA nanoparticle had substantial changes in yield stress values, but no effect was observed when HT had been isolated. Two thixotropic models were analyzed for the epoxy system, and the better performance was observed for the model with two rheological parameters. The presence of nanoparticule in epoxy coating reduced around 40% the recovery time. The addition of nanoparticules changes the rheological properties of a commercial coating. The X-Rays Diffraction analyses were done to observe the dispersions degree and exfoliations in the epoxy system. The crystalline peak of nanoparticles had lost for all coating formulations. The electromagnetic interference shielding attenuation was 60% in the formulations with high content of both nanoparticles. The APA and HT improved hence, the anticorrosion performance of the epoxy coating for 720 h in chloride solution. Corrosion resistance had the best performance in the coating with high concentration of carbon black and nanoparticles.