改性氟化石墨烯增强氟树脂防腐蚀涂层的制备及性能

Preparation and properties of modified fluorographene-reinforced anticorrosive fluororesin composite coating

以氟化石墨(FGi)为原料,先后采用热插层法和改进的Hummers法制备得到氟化石墨烯(FG)和氧氟化石墨烯(OFG),再用氨丙基三乙氧基硅烷(KH550)对OFG进行接枝改性得到KH550-OFG。通过原子力显微镜、傅里叶变换红外光谱和X射线衍射分析了改性氟化石墨烯的微观形貌和组织结构。随后将KH550-OFG作为防腐蚀填料,制备了氟树脂(PFA)基复合涂层(记为P-OFG),通过电化学阻抗谱测量、气密性测试及中性盐雾试验研究了P-OFG复合涂层的防腐蚀性能。结果表明,对FG进行表面处理和接枝改性可以提高其在氟树脂中的分散性,有效延长腐蚀介质在涂层基体中的渗透路径,增强涂层的防腐蚀性能。P-OFG复合涂层的气密性优于PFA涂层,在1%(质量分数)硫酸溶液中浸泡60 d后依然表现出较佳的防腐蚀性能。

Fluorographene(FG)and oxidized fluorographene(OFG)were prepared from fluorinated graphite(FGi)respectively by intercalation method and modified Hummers method.OFG was then grafted with aminopropyltriethoxysilane(KH500),forming a KH500-modified OFG(coded as KH550-OFG).The morphology and microstructure of the modified fluorographene were characterized by atomic force microscopy,Fourier-transform infrared spectroscopy,and X-ray diffraction.A fluororesin(PFA)-based composite coating(coded as P-OFG)was obtained using the KH550-OFG as anticorrosive filler.The corrosion resistance of P-OFG composite coating was studied by electrochemical impedance spectroscopy(EIS),air tightness test,and neutral salt spray test.The results showed that the dispersibility of FG in fluororesin could be improved by surface treatment and grafting,effectively extending the penetration path of corrosive medium in coating matrix and enhancing the anticorrosion performance of coating.The P-OFG composite coating featured better air tightness than PFA coating,and showed good corrosion resistance after being immersed in 1%(mass fraction)sulfate acid solution within 60 days.