Protective Performance of Water-Based Epoxy Coating Containing ScCO2 Synthesized Self-Doped Nanopolyaniline

TL;DR

This study demonstrates that incorporating supercritical CO2 synthesized self-doped nanopolyaniline into water-based epoxy coatings significantly enhances their corrosion resistance, adhesion, and protective performance in saline environments.

Contribution

It introduces a novel water-based epoxy coating with nanopolyaniline synthesized via supercritical CO2, improving corrosion protection compared to traditional coatings.

Findings

Enhanced electrical resistance after 1800 hours of salt spray exposure.

Improved adhesion and oxide layer formation observed in SEM analysis.

Significantly higher impedance indicating better corrosion resistance.

Abstract

In this research, corrosion properties of water-based epoxy coating is improved by adding self-doped nano polyaniline (SPAni) synthesized using supercritical carbon dioxide (ScCO2) medium. The modified ScCO2-synthesized self-doped nano polyaniline (SPAni) using water-based polyamidoamine hardener results formation of the water-based SPAni composite (Sc-WB). To obtain the water-based polyaniline epoxy coating (SP-WBE), the Sc-WB was mixed with epoxy resin in stoichiometric ratio. The formation of oxide layers and adhesion properties of SP-WBE at corrosive medium was evaluated using scanning electron microscopy (SEM) studies. The transmission electron microscopy (TEM) was used to observe the distribution and particles size of nanopolyaniline in the final dried film. The anti-corrosion performance of water-based epoxy coated sample (blank coated sample) and SP-WBE coated sample was studied using salt spray standard test according to ASTM B-117, electrochemical impedance spectroscopy (EIS) and adhesion tests. The results indicate protective performance of water-based epoxy coating is improved by adding self-doped polyaniline synthesized at ScCO2 situation. The electrical resistance of the coatings containing nanopolyaniline and the blank sample was 1.8778E+7 {\Omega}.cm2 and 2.512E+5 {\Omega}.cm2 after 1800 hours of immersion in 3.5 Wt% NaCl aqua corrosive solutions.