Self-healing effect of epoxy coating containing mesoporous polyaniline hollow spheres loaded with benzotriazole

Abstract

Recently, people pay more attention to the application of mesoporous nanomaterials in organic coatings owing to their high corrosion inhibitor loading rate, which could strongly improve organic coatings anticorrosion performance. However, traditional nanomaterials were used only as the hosts for corrosion inhibitors because they do not have corrosion inhibition function, which restricted the further improvement of the anticorrosion performance of organic coatings. If the mesoporous materials have corrosion inhibition function, it will be inferred to further improve the coating performance.To address this problem, a novel mesoporous nanomaterial: mesoporous polyaniline hollow spheres (MPHS) were synthesized using mesoporous carbon hollow spheres (MCHS) as the hard template and PS100-b-PEO114 as the soft template. MPHS loaded with benzotriazole (MPHS@BTA) was introduced into epoxy coating as an anticorrosion pigment, and then the anticorrosion properties of epoxy coatings were systematically investigated.The BET surface area, total pore volume and average pore diameter of MPHS were 568 cm2 g−1, 1.3 cm3 g−1 and 8.9 nm, respectively. Due to high specific area and high pore volume, the loading rate of BTA in MPHS was up to 27 wt%. Epoxy coating blended with 2 wt% MPHS@BTA presented the best anticorrosion and self-healing properties, which was ascribed to the synergistic effect of the passivation function of PANI and the corrosion inhibition effect of BTA.