The Epoxy Zinc-Rich Coatings (Zrcs) Mechanical and Anti-Corrosion Characteristics Improvement Utilizing Zif-8/Polyaniline Nanoparticles

Zinc-rich coatings (zrcs) are widely used in the coating industry due to their excellent anti-corrosion properties. these coatings protect metal surfaces mainly by two well-known mechanisms: 1. galvanic protection during earlier stages and 2. barrier protection during later stages of their service life. however, the current zrc systems suffer from high cost and limited galvanic protection serving life due to the fast consumption of the zinc particles which results in a high fraction of the unreacted zinc particles. to address this issue, we have developed a novel zrc system based on zeolitic imidazolate framework-8 (zif-8) and polyaniline (pani) particles with superior mechanical and anti-corrosion properties. ft-ir, xrd, sem, and raman spectroscopy were employed to prove the successful synthesis of zif-8 and pani particles. no iron corrosion products appeared at the surface of the samples after 30 days of exposure to the salt-spray test (sst). pull-off test results indicated that the addition of 1 wt.% zif-8 can increase the adhesion of zrcs by more than 250%. the sample containing 0.5 wt.% zif-8/0.5 wt.% pani had the least adhesion loss after 30 days of exposure to sst. moreover, the zrc system with 0.5 wt.% zif-8/0.5 wt.% pani demonstrated the highest impact (direct and indirect) resistance among the prepared coating systems. taken together, the results have shown that partial replacement of zinc dust with a combination of zif-8 and conductive pani particles is a cost-effective method to improve the mechanical and anticorrosion characteristics and to prolong the service life of zrc systems.

The epoxy zinc-rich coatings (ZRCs) mechanical and anti-corrosion characteristics improvement utilizing ZIF-8/polyaniline nanoparticles

Zinc-rich coatings (ZRCs) are widely used in the coating industry due to their excellent anti-corrosion properties. These coatings protect metal surfaces mainly by two well-known mechanisms: 1. galvanic protection during earlier stages and 2. barrier protection during later stages of their service life. However, the current ZRC systems suffer from high cost and limited galvanic protection serving life due to the fast consumption of the zinc particles which results in a high fraction of the unreacted zinc particles. To address this issue, we have developed a novel ZRC system based on zeolitic imidazolate framework-8 (ZIF-8) and polyaniline (PAni) particles with superior mechanical and anti-corrosion properties. FT-IR, XRD, SEM, and Raman spectroscopy were employed to prove the successful synthesis of ZIF-8 and PAni particles. No iron corrosion products appeared at the surface of the samples after 30 days of exposure to the salt-spray test (SST). Pull-off test results indicated that the addition of 1 wt.% ZIF-8 can increase the adhesion of ZRCs by more than 250%. The sample containing 0.5 wt.% ZIF-8/0.5 wt.% PAni had the least adhesion loss after 30 days of exposure to SST. Moreover, the ZRC system with 0.5 wt.% ZIF-8/0.5 wt.% PAni demonstrated the highest impact (direct and indirect) resistance among the prepared coating systems. Taken together, the results have shown that partial replacement of Zinc dust with a combination of ZIF-8 and conductive PAni particles is a cost-effective method to improve the mechanical and anticorrosion characteristics and to prolong the service life of ZRC systems.