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环氧树脂(EPRs)因其良好的耐蚀性、耐化学品性、黏附性及低固化收缩率而广泛应用于防腐蚀涂层。由有机硅烷或线性聚硅氧烷出发,经前者的水解、缩合及两者与EPR的加成等反应,将疏水性良好的有机硅树脂(SR)凝胶或链段作为(EPR-填料)偶联层、(金属基底)底漆、(分散或互穿聚合物网络)相、或(共聚)组分引入到EPR固化涂层体系中,可以通过疏水阻隔及凝胶相或交联点(链段)缓蚀的机理提高改性EPR涂层的防腐蚀性能;SR的体积分数效应亦改善了涂层的耐老化性与耐热性。在无水催化条件下,经有机硅烷的烷氧基与EPR的羟基之间的醇解(缩合)反应,生成硅烷小分子接枝改性EPR固化涂层;亦能通过体系中未反应的烷氧基的水消化(水解)阻隔改良涂层的防腐蚀性能。当向SR改性EPR涂层中加入陶瓷(纳米氧化物、粘土、碳材料)填料时,适中的含量可能导致独特的树脂-陶瓷两相形态而产生结构性疏水;当引入无机酸盐(铬酸盐、磷酸盐、硅酸盐、稀土铈盐、钼酸盐、高锰酸盐)或有机化合物(8-羟基喹啉、四氯代苯对醌)转化膜或颗粒时,可能在涂层-金属界面处发生转化保护型电化学防护;而当填充低电位活性金属(Mg、Zn)粉末时,则可能在金属基底表面形成阴极保护型电化学防护;同时,所有三种填料的加入均可能进一步增强涂层的缓蚀效应。在调控与优化EPR-SR体系结构与形态的同时,辅以各种改性填料的协同耦合使用,成为实现SR改性EPR涂层防腐蚀性能最佳化的必经途径之一。
Epoxy resins (EPRs) are widely used in corrosion protection coatings due to their good corrosion resistance, chemical resistance, adhesion and low cure shrinkage. Starting from organosilanes or linear polysiloxanes, the hydrophobic or good silicone resin (SR) gels or segments react with (EPR-filler) through the former’s hydrolysis, condensation and reaction with EPR, The coupling layer, (metal substrate) primer, (dispersed or interpenetrating polymer network) phase, or (co) component is incorporated into the EPR cured coating system via hydrophobic barrier and gel phase or crosslinking point ( Chain) corrosion inhibition mechanism to improve the corrosion resistance of modified EPR coating; SR volume fraction effect also improves the coating’s resistance to aging and heat resistance. Under the condition of anhydrous catalysis, the silane-based small molecule graft modified EPR cured coating is formed through the alcoholysis (condensation) reaction between the alkoxy of the organosilane and the hydroxyl of the EPR; and the unreacted alkyl Water digestion (hydrolysis) of oxygen groups improves the corrosion protection of the coating. When fillers of ceramic (nano-oxide, clay, carbon material) are added to the SR-modified EPR coating, the moderate content may result in a unique resin-ceramic two-phase morphology resulting in structural hydrophobicity. When the inorganic acid salt Phosphates, silicates, rare earth cerium salts, molybdates, permanganates) or organic compounds (8-hydroxyquinoline, tetrachlorobenzene p-quinone) conversion film or particles may be in the coating - conversion protection electrochemical protection occurs at the metal interface; when the low-potential active metal (Mg, Zn) powder is filled, cathodic protection electrochemical protection may be formed on the metal substrate surface; meanwhile, all three filler additions May further enhance the corrosion inhibition effect of the coating. It is one of the necessary ways to optimize the anti-corrosion performance of SR-modified EPR coatings while controlling and optimizing the structure and morphology of the EPR-SR system, combined with the synergistic coupling of various modified fillers.