不同酸掺杂聚苯胺/环氧涂层的防腐蚀性能研究

Study on corrosion resistance of epoxy coatings containing polyaniline doped with different acids

制备了分别由盐酸、硫酸、磷酸、植酸、甲基磺酸和十二烷基苯磺酸掺杂的聚苯胺(依次记为HCl-PANI、H2SO4-PANI、H3PO4-PANI、PA-PANI、MSA-PANI和DBSA-PANI)与本征态聚苯胺(EB-PANI),通过傅里叶变换红外光谱仪、紫外可见分光度计、X射线衍射仪、拉曼光谱仪及扫描电镜对它们的结构与形貌进行了表征。将不同的聚苯胺材料分别添加到环氧树脂中并涂覆在Q235碳钢表面,得到不同的聚苯胺/环氧(PANI/EP)涂层,对其铅笔硬度、附着力及湿润性进行测试,并通过电化学阻抗谱考察了它们在3.5%NaCl溶液中的耐蚀性,讨论了不同添加量、不同掺杂酸对聚苯胺/环氧涂层耐蚀性的影响。结果表明上述7种聚苯胺均呈珊瑚状结构。添加了聚苯胺的环氧涂层的防腐性能得到了不同程度的提高,其中聚苯胺的最佳添加量为0.6%,HCl-PANI与PA-PANI的效果最好。

Polyaniline(PANI)doped with different acids i.e.hydrochloric acid,sulfuric acid,phosphoric acid,phytic acid,methanesulfonic acid,dodecylbenzenesulfonic acid,and intrinsic polyaniline were prepared and coded as HCl-PANI,H2SO4-PANI,H3PO4-PANI,PA-PANI,MSA-PANI,DBSA-PANI,and EB-PANI,respectively.The microstructure and morphology of the polyaniline materials were characterized by Fourier-transform infrared spectroscopy,ultraviolet-visible spectrophotometry,X-ray diffraction,Raman spectroscopy,and scanning electron microscopy.The polyaniline materials were added to an epoxy resin and then coated on the surface of Q235 carbon steel to form different polyaniline/epoxy(PANI/EP)coatings.The pencil hardness,adhesion,and wettability of PANI/EP coatings were tested,and their corrosion resistance in 3.5%NaCl solution was studied by electrochemical impedance spectroscopy.The effects of the dosage and doping acid of PANI on the corrosion resistance of PANI/EP coating were discussed.The results showed that all the seven types of PANI had a coral-like morphology.The anticorrosion performance of epoxy coating was improved to various degrees by addition of different PANI materials,especially HCl-PANI and PA-PANI.The optimal dosage of PANI was 0.6%by mass.