石墨微片/环氧复合防腐涂料的制备及防腐机制  

Preparation of graphite nanosheets/epoxy anti-corrosive coating and its anti-corrosion mechanism

作　　者：刘立柱[1,2] 张佳文 徐航 都书强 张笑瑞[1,2] LIU Lizhu;ZHANG Jiawen;XU Hang;DU Shuqiang;ZHANG Xiaorui(School of Materials Science ＆ Engineering,Harbin University of Science and Technology,Harbin 150080,China;Engineering Dielectric and Application Technology Main Lab,Harbin 150040,China)

机构地区：[1]哈尔滨理工大学材料科学与工程学院,哈尔滨150080 [2]工程电介质及其应用技术教育部重点实验室,哈尔滨150040

出　　处：《复合材料学报》2018年第7期1738-1744,共7页Acta Materiae Compositae Sinica

基　　金：黑龙江省大学生创新训练项目(201710214028)

摘　　要：以水性环氧乳液(EP emulsion)及其固化剂为基体,加入石墨微片(GNs)制备防腐涂料,并分析防腐机制。通过盐雾时间测试发现GNs用量为EP emulsion中EP质量的4%时,其耐盐雾时间最长为240h,同时其200h划十字线的腐蚀距离低于市售Fe2O3/EP涂料。从GNs/EP emulsion复合防腐涂料漆膜表面的SEM图像可以发现,GNs分散的越均匀,涂膜的防腐能力越强。通过Tafel极化曲线发现,该含量漆膜具有腐蚀电位高和腐蚀电流小的特点,这是由GNs在环氧树脂中均匀分布形成微观电容提高树脂介电常数,进而提高漆膜电荷储存能力,减弱电子移动能力而实现的,并借助Nyquist曲线及漆膜断面的SEM图像,建立等效电路及石墨微电容防腐模型。研究发现,GNs/EP emulsion防腐涂料的防腐机制是通过借助GNs的化学稳定性对水和氧气的物理隔绝作用以及通过微电容的形成减弱电子移动能力的电化学作用共同实现。The anti-corrosive coating was prepared by graphite nanosheets （GNs）, epoxy emulsion （EP emulsion） and its curing agent, and the anti-corrosive mechanism of the GNs/EP emulsion anti-corrosive coating with graphite was analyzed. The best GNs amount is 4% of epoxy resin in EP emulsion, as a result of the salt spray testing, with the breaking time is 240 h, and its corrosion under the scribe line or an area of damaged edge corroded for 200 h is smaller than the Fe2O3/EP coating. The anti-corrosive ability of the GNs/EP emulsion coating is enhanced by the improvement of the GNs distribution, as could be seen from the SEM images of the coating surface. GNs/EP emul sion coating film has the higher corrosion potential and smaller corrosion current listed in the Tafel testing, as the result of the dielectric constant increased by the miniature capacitor formed with epoxy and well distributed GNs, the electric charge storage ability is enhanced and the electron transfer ability is reduced by this. As a result, the anti corrosive model of GNs/EP emulsion coating is formed employing the Nyquist diagrams and the SEM images of GNs/EP emulsion coating cross section. The function of the anti corrosive GNs/EP emulsion coating is attribute by the physical function to defend the H2O and O2 employing the high chemical stability of GNs and the electrochemis try function to reduce the electron transfer ability by forming the miniature capacitor.

关 键 词：防腐涂料 石墨微片 环氧乳液 微电容模型 等效电路 防腐机制 

分 类 号：TB332[一般工业技术—材料科学与工程]