以负载缓蚀剂的二氧化硅微胶囊制备水性智能防腐涂料及其涂层性能研究

摘要

将缓蚀剂苯并三氮唑(BTA)溶解在水中,利用正硅酸乙酯在水存在的条件下会发生缩合反应的特点,在反相体系中生成二氧化硅(SiO2)微球,以其作为载体包覆BTA,制备成负载缓蚀剂的微胶囊(SiO2/BTA),然后用六甲基二硅胺烷对其进行改性以提高其疏水性,并通过扫描电镜和红外光谱仪进行了表征.将微胶囊与苯丙乳液制备成水性防腐涂料,考察了涂层的耐蚀性和力学性能,并与不含SiO2和BTA或含其中之一的涂料所制涂层的性能进行对比.缓蚀剂的缓慢释放能延缓涂料缺陷引起的腐蚀,显著提高涂层的耐蚀性.当微胶囊的含量为1.5%时,涂层的综合性能最佳.%Microcapsules loaded with benzotriazole (BTA, a corrosion inhibitor), coded as SiO2/BTA, were prepared in an aqueous BTA-containing solution based on a condensation reaction of tetraethoxysilane in presence of water forming SiO2 microspheres in phase inversion, which act as carriers to encapsulate BTA. The SiO2/BTA microcapsules were modified by hexamethyldisilazane to improve their hydrophobicity and then characterized by scanning electron microscopy and infrared spectroscopy. A water-based anticorrosive coating material was obtained based on styrene-acrylate emulsion with the SiO2/BTA microcapsules. The corrosion resistance and mechanical properties of the coating obtained therefrom were examined and compared with those of the coatings prepared without SiO2and/or BTA. The slow release of corrosion inhibitor retards the corrosion caused by coating defects, improving the corrosion resistance of coating greatly. The coating containing 1.5% of SiO2/BTA microcapsules has the optimal comprehensive performance.