无机酸掺杂聚吡咯/环氧复合涂层的制备及其耐蚀性

Preparation of inorganic acid doped polypyrrole/epoxy composite coating and its corrosion resistance

采用化学氧化聚合法分别制备了盐酸、硫酸、硝酸及磷酸掺杂的聚吡咯(HCl-PPy、H2SO4-PPy、HNO3-PPy和H3PO4-PPy)。用扫描电镜、傅里叶变换红外光谱仪和X射线衍射仪表征了掺杂聚吡咯的形貌和结构。将掺杂态聚吡咯与E44环氧树脂混合均匀,刷涂在Q235钢表面制得PPy/EP复合涂层,并通过电化学阻抗谱和加速浸泡试验考察了它们在3.5%NaCl溶液中的耐蚀性。4种无机酸掺杂聚吡咯都呈圆球颗粒状,部分有团聚现象。添加PPy明显提高了环氧涂层对碳钢的防腐作用,其中H3PO4-PPy的效果最好。

Polypyrrole doped with hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid respectively(HCl-PPy, H2SO4-PPy, HNO3-PPy, and H3PO4-PPy) were prepared by chemical oxidation polymerization. The morphology and structure of the doped polypyrrole were characterized using scanning electron microscope, Fourier-transform infrared spectrometer, and X-ray diffractometer. The doped polypyrrole and E44 epoxy resin were blended uniformly, and then brushed on the surface of Q235 mild steel, forming four types of PPy/EP composite coatings. Their corrosion resistance in 3.5% NaCl solution were studied by electrochemical impedance spectroscopy and accelerated immersion testing. The four types of inorganic acid-doped polypyrrole are spherical particles with some agglomeration. The addition of PPy, especially H3PO4-PPy, obviously improves the anticorrosion efficacy of epoxy coating on carbon steel.