Preparation And Properties Of Nano-Al₂O₃/Epoxy Resin Composite Anticorrosive Coatings

In recent years,more and more metal materials have been used to develop marine resources.However,the metal corrosion caused by the peculiarities of the marine environment not only affects the growth of the national economy,but also poses a threat to human life.Therefore,the use of organic coatings to protect steel structure materials is currently the most widely used and most affordable method.The most widely used anti-corrosion coating in organic coatings is epoxy resin coatings,but it is brittle and has poor impact resistance,so it needs to be modified.The discovery of nanoparticles provides a new method for modifying epoxy resins.In this paper,the surface modification of nano-alumina with silane coupling agent?KH-550?was added to epoxy resin to prepare nano-alumina/epoxy composite anti-corrosion coating.Impact resistance,abrasion resistance and anti-corrosion performance were analyzed and tested,and the action mechanism of nanoparticle modified epoxy resin and the anti-corrosion mechanism of the coating were preliminarily discussed.The main results are as follows:1.The hardness,adhesion,abrasion resistance and other properties of nano-alumina/epoxy resin composite anticorrosive coatings increase with the increase of nano-particle content,but begin to decrease after exceeding a certain range.When the addition amount of nano-alumina is 5wt.%,The coating adhesion is increased by 64%,and the impact strength is increased by 180%.2.When the amount of nano-alumina is small,although it is dispersed uniformly in the coating,the wear resistance of the coating is not significantly improved due to the small content.When the amount of nano-alumina is small,large amounts of accumulation occur and agglomeration occurs.The integrity of the coating is compromised.When the content is 5wt.%,The dispersibility of the nanoparticles is the best,and the density of the coating is the best.3.The anti-corrosion performance of nano-alumina/epoxy resin composite anti-corrosion coating shows a trend of first increase and then decrease with the increase of nano-alumina particles.When the amount is 5wt.%,The coating achieves the best anti-corrosion performance.After 40 days of immersion in simulated seawater,the impedance modulus of the coating remained above 10¹⁰?·cm2,showing good corrosion resistance.4.The modified nano-alumina is uniformly dispersed in the epoxy resin system.On the one hand,it compensates for the defects caused by the curing of the coating and improves the compactness of the coating.In addition,the presence of nano-alumina particles also increases the corrosion medium.The permeation path delays the contact time with the metal substrate and enhances the corrosion resistance of the composite coating.On the other hand,the nanoparticles can also absorb the energy generated when the coating is impacted by an external force,and hinder the expansion of the silver texture,thereby improving the toughness of the coating.