聚吡咯涂层的制备及耐腐蚀性能研究

目的在铜表面制备聚吡咯涂层,研究其在3.5%(质量分数)Na Cl溶液中的耐腐蚀性能。方法采用恒电位法、恒电流法和循环伏安法在铜表面制备聚吡咯薄膜,用扫描电子显微镜观察聚吡咯膜形貌,用动电位极化曲线、长期浸泡实验研究铜表面聚吡咯膜的防腐蚀情况。结果三种方法都可以在铜表面形成结构致密、结合力较好的呈菜花状结构的聚吡咯膜。聚吡咯膜在3.5%(质量分数)Na Cl溶液中的极化曲线与空白铜不同,形成了钝化区。在60 min,0.659 V和60 min,1 m A条件下制备的聚吡咯膜的腐蚀电位与空白铜片相比,分别提高了约50 m V和150 m V,阳极溶解电流密度比空白铜片均降低了1个数量级。在长期浸泡实验中,带有聚吡咯膜的铜片的腐蚀速度低于空白铜片。结论聚吡咯膜可以延缓铜片的腐蚀,恒电位法制备的聚吡咯膜具有更优良的耐蚀性能。

Preparation and Corrosion Performance of Polypyrrole Film

Objective To prepare the polypyrrole film on the copper surface and study its corrosion resistance in 3. 5% NaCl solution. Methods Polypyrrole films were electrodeposited on the copper surface using potentiostatic, galvanostatic and cyclic voltammetry electrochemical techniques. Scanning electron microscope was used to observe the surface morphologies of polypyrrole. The anticorrosion performance of polypyrrole films was studied by the potentiodynamic polarization curves and long-term immersion test. Results Compact and highly adhesive polypyrrole film with cauliflower shaped structure could be formed on the copper surface by all the three methods. The polarization curves of Polypyrrole film in 3. 5% NaCl solution showed passivation region, which was different from that of bare copper. The corrosion potentials of polypyrrole films formed at 0. 659 V,60 min and 1 mA,60 min were higher by 50 mV and 150 mV than that of bare copper, respectively. Compared to the bare copper, the anodic dissolution current density of polypyrrole films was reduced by about one order of magnitude. In the long-term immersion test, the corrosion rate of copper with polypyrrole film was lower than that of bare copper. Conclusion Polypyrrole film could delay the corrosion of copper. The film prepared by potentiostatic technique provided a better protection performance.