聚苯胺/纳米La_2O_3/环氧树脂复合涂层在NaCl溶液中的腐蚀行为

Corrosion Behavior of Composite Coating of Polyaniline/Nano-La_2O_3/Epoxy Resin in NaCl Solution

将聚苯胺/纳米La2O3复合粒子作为填料制成环氧树脂防腐涂料,涂于经处理过的低碳钢试样上;将该试样浸泡在3.5%NaCl溶液中,测试交流阻抗和极化曲线。实验结果表明:随苯胺与氧化镧比例由0∶5、1∶50、1∶25到1∶10变化,涂层防腐蚀性能逐渐增强,比例为1∶25时最强;涂层表面电荷与金属表面电荷交换由易到难、再到容易转变;苯胺与氧化镧比例为1∶25时,涂层的微孔电阻Rp最大,屏蔽性能最好,电容值最小,耐渗透性能最好。

The composite coating was prepared by introducing polyaniline/nano La2O3 as a filling agent into epoxy resin. The corrosion resistance of the composite coating was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy in NaCI solution. The results showed that with changing ratio of aniline and La2O3 from 0：5,1：50,1：25 to 1 ： 10, the corrosion resistance gradually increased; when the ratio was l ： 25, corrosion resistance the most strongest. The charge ex- change between coating surface and metal surface changed from easy to difficult, and then easy. When the ratio of polyaniline and La2O3 was 1：25 ,micropore resistance Rp for coating reached a maximum,the shielding performance was the best, the ca- pacitance C value was the smallest, and permeability resistance was the best.