Eco-friendly waterborne basalt epoxy anti-corrosion primer for rusty steel

This work aims to develop a novel eco-friendly waterborne epoxy anti-corrosion primer for rusty steel. The basalt flakes and polyaniline-modified TiO 2 were used as pigment to replace zinc, and multi-organic acids were used as conversion agents based on the film-forming of waterborne epoxy emulsion. Their effects on the adhesion and anti-corrosion were studied using cross-cut test, electrochemical test station and neutral salt spray test, respectively. The microstructures of the coatings were also tested to analyze the anti-corrosion mechanism. The results show that Tannic + Citric + Gallic has the best rust conversion effect. The coating with 10% basalt flakes, 3% polyaniline-modified TiO 2 has a uniform and dense diffusion barrier layer. The adhesion is the highest with grade 0. The corrosion resistance is the best with high corrosion impedance and high salt spray resistance time of 480 h. It provides a new option for the rusty steel structures to maintain against corrosion in practical engineering applications.