聚苯胺/环氧涂层对AZ91D镁合金耐蚀性能的影响

EFFECT OF PANI/EPOXY COATING ON THE CORROSION RESISTANCE OF AZ91D MAGNESIUM ALLOY

通过化学氧化法合成本征态及氢氟酸掺杂态聚苯胺(PANI),用红外光谱对其结构进行表征。以环氧树脂为成膜物质,在AZ91D镁合金基体上制备了本征态及氢氟酸掺杂的PANI/环氧涂层,用EIS方法研究涂层在3.5%NaCl溶液中的耐蚀性,并用SEM对浸泡后基体表面形貌进行观察。实验结果表明,与环氧清漆相比,本征态PANI的加入明显改善了环氧涂层的耐蚀性,而氢氟酸掺杂后进一步提高了PANI/环氧涂层的性能。用XPS对基体表面分析,发现添加聚苯胺的涂层在镁合金表面形成了具有保护作用的产物膜。

The chemical oxidative method was applied to prepare the eigenstate polyaniline（PANI） and hydrofluoric acid doped PANI,whose structure was characterized by FT-IR.Epoxy resin was used as the filmforming substance and to prepare the eigenstate PANI and hydrofluoric acid doped PANI/epoxy coating on AZ91D magnesium alloy surface,and their anti-corrosion properties were studied by means of electrochemical impedance spectroscopy（EIS） in 3.5%NaCl solution.The surface morphology of AZ91D magnesium alloy after immersion was observed by SEM.The results indicated that the addition of eigenstate PANI could significantly improved the corrosion resistance of epoxy varnish coating.However,hydrofluoric acid doped PANI/epoxy coating had better corrosion resistance than eigenstate PANI/epoxy coating.XPS results indicated that the presence of polyaniline changed the chemical structure of the corrosion film on the alloy surface.