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.

Rheology, curing and time‐dependent behavior of epoxy/carbon nanoparticles systems

“…This results in a stratified structure that offers less resistance to flow and is primarily governed by hydrodynamic forces. Suspensions that tend to form networks when at rest tend to exhibit more pronounced shear thinning behavior 43,44 . This behavior is known as shear‐thinning and is caused by many factors, such as chemical modification of particles and others.…”

“…Suspensions that tend to form networks when at rest tend to exhibit more pronounced shear thinning behavior. 43,44 This behavior is known as shear-thinning and is caused by many factors, such as chemical modification of particles and others. In the current work, it may be related to a hierarchical structure of aggregated CNT.…”

Influence of the Addition of Sialon and Aluminum Nitride Fillers on the Photocuring Process of Polymer Coatings

“…The increase in viscosity stems mostly due to the interfacial friction between the fillers and between fillers and the dispersing medium. Due to Brownian movement or interactions that induce relative motion of particles, the microstructure can be rebuilt as the flow decreases or stops and, in some cases, forms a space-filling structure network [21].…”

Estudos reológicos e de blindagem eletromagnética de tinta acrílica comercial modificada com goma xantana e negro de fumo

“…A tinta acrílica comercial apresenta recuperação inferior ao valor inicial, o que caracteriza deformações irreversíveis na estrutura. Amorim (2021) estudou o efeito provocado pela adição de nano partículas e cargas condutoras em resina epoxi, a recuperação provocada pela estruturação da resina melhora a aplicabilidade da tinta. O ajuste do modelo da lei de WLF para as curvas de viscosidade, eq (4), a temperatura de referência foi de 30°C, (T0).…”

“…As propriedades finais das tintas podem ser ajustadas em função da aplicação final, as principais modificações são no peso molecular e nos aditivos utilizados nas formulações (Pires Neto, et.al. 2019;Amorim, et. al., 2021).…”