Accelerated Corrosion tests of epoxy-based coatings containing zinc tannates

Accelerated corrosion tests were performed to evaluate the efficiency of epoxy paints (primers) prepared with different anticorrosive pigments to protect structural steel. Nowadays, sustainable technology goals in the paint industry seek to replace the widely used conventional anticorrosive pigments, such as lead or chromate, because of their harmful toxicity to the environment and human health. Previous studies on alkyd coatings have shown that zinc tannates prepared with Tara tannins have the necessary requirements to be considered an efficiently, green and low-cost alternative for prevention of corrosion. Results showed that epoxy primers formulated with zinc tannates exhibited an equivalent anticorrosive behavior to phosphate base coatings and an equivalent or superior performance to those prepared with zinc chromate after salt spray (3500 h) and sulfur dioxide (2500 h) accelerated tests.