Preparation And Properties Of Stimulus Response Self-Healing Anticorrosion Coating

Metal materials have excellent mechanical properties and craftsmanship,and play an incomparable role in many fields such as chemical engineering,medical instruments,construction,electrical devices and so on.However,metal materials are prone to corrosion and metal corrosion is a pervasive destructive phenomenon.Which has caused substantial pecuniary losses,severe environmental pollution and even resulted in serious security accidents.Therefore,taking effective measures to suppress metal corrosion is of great significance to the development of society.Coating protection is one of the most effective methods to develop anticorrosion systems.Unfortunately,traditional anticorrosive coatings,such as epoxy resin,phenolic resin,polyurethane,etc.,will inevitably be broken by environmental or mechanical effect in the long-term use process.Once the physical barrier of the coating fails,the corrosive medium will easily penetrate into the metal substrate,causing corrosion of metal materials.In recent years,inspired by the damage-healing capability of living organisms,the intelligent anticorrosion coating that can recover original performance after being damaged and achieve long-term protection of metal have attracted increasing research attention.Which shows an extensive application prospect in the domain of metal preservation,and is worthy of making further efforts to exploration.In this study,a stimulation response self-healing system is designed and prepared,and it was applied to coating to prepare intelligent self-healing anticorrosive coating.When the coating is damaged,the intelligent self-healing system can protect metal timely by releasing corrosion inhibitor in response to stimulation.The specific research contents are as follows:1.A self-healing anticorrosion coating with redox response was designed and prepared on metal substrate for corrosion protection.The composite coating displayed desirable redox response,mainly due to the polyurethane acrylate（PUA）with disulfide bond conjugate inhibitor（MBTS₂MA）.Indeed,the disulfide bonds can be cleaved in a reducing environment,yielding controlled release of the corrosion inhibitor 2-mercaptobenzothiazole（MBT）during metal corrosion process.Additionally,graphene oxide nanosheets（GO）were introduced before coating curing.The introduction of GO can greatly enhance the barrier property of composite coating and reduce the penetration of corrosive medium.MBT and GO by forming an active protective film with metal substrates and improving the passive barrier performance of the coating,respectively,thereby greatly enhancing the anticorrosion property of the coating.This intelligent self-healing coating will exhibit great application prospects in corrosion protection.2.A dual self-healing anticorrosion coating with pH and thermal response was fabricated by integrating corrosion inhibitor nanocontainers（MSN-MBT）and wax into the epoxy coating.Encapsulated corrosion inhibitor MBT released from the nanocontainers in a pH-controlled manner and rapidly inhibit the corrosion reaction activities.Meanwhile,the temperature of coating rose rapidly under heating conditions,so wax could repair coating damage within 5 mins and effectively restore the passive barrier property of the coating.In addition,the wax endowed the composite coating repeatable self-healing properties and the self-healing performance was well maintained even after five scratch-heating cycles.EIS test results showed that the composite coating has excellent corrosion resistance and could effectively block the penetration of corrosive media,providing long-term corrosion protection for metals.This self-healing anticorrosion system solves the problem that previous coating without repeatable self-healing performance,providing new ideas for preparation of the intelligent self-healing anticorrosion coating.