三聚氰胺改性纳米SiO2水性环氧涂层的制备及防腐性能

Preparation and anticorrosive properties of waterborne epoxy coating of melamine modified nano silica

摘要:

以3-氯丙基三乙氧基硅烷(CPTES)为端基改性剂,制备氯端基化的SiO2(CTNS),再引入三聚氰胺(MA)作为腐蚀抑制剂,通过共价键的进一步修饰接枝到CTNS表面,制备三聚氰胺修饰纳米二氧化硅(MCTNS)复合材料。FTIR、XPS、热重等测试表征了MCTNS复合材料的成功合成；将该复合材料与水性环氧树脂共混制备水性环氧复合涂料,通过电化学分析和盐雾实验对涂层的防腐性能进行了探究,并通过冲击实验和附着力测试等分析了涂层的物理性能。结果表明,添加质量分数为1.0%的MCTNS涂层物理性能优异(附着力0级、硬度3H、耐冲击45 Kg?cm、吸水率4.28 %)；与纯水性环氧树脂(WEP)涂层相比,腐蚀电流密度从9.13×10-5A?cm-2减小至8.13×10-6 A?cm-2,腐蚀电位从-0.597V增大到-0.248V,缓蚀效率可达97.5%,盐雾试验30d后涂层仍能保持光滑完整。

Abstract:

Chloropropyl triethoxysilane (CPTES) was used as end-group modifier to prepare chloro-terminated SiO2 (CTNS), and melamine (MA) was introduced as a corrosion inhibitor, and further modified by covalent bond to CTNS surface to prepare melamine modified nano-silica (MCTNS) composite. The successful synthesis of MCTNS composites was characterized by FTIR, XPS and thermogravimetric tests. The waterborne epoxy composite coating was prepared by blending the composite material with water-based epoxy resin. The anti-corrosion properties of the coating were investigated by electrochemical analysis and salt spray test. The physical properties of the coating were analyzed by impact test and adhesion test. The results show that the coating with 1.0% MCTNS has excellent physical properties (adhesion grade 0, hardness 3H, impact resistance 45 Kg·cm, water absorption 4.28%). Compared with the pure waterborne epoxy resin (WEP) coating, the corrosion current density decreases from 9.13×10-5A·cm-2 to 8.13×10-6 A·cm-2, the corrosion potential increases from -0.597V to -0.248V, the corrosion inhibition efficiency reaches 97.5%, and the coating remains smooth and complete after 30 days of salt spray test.