改性石墨烯对环氧树脂涂层耐腐蚀性能的影响

将改性后石墨烯粉末通过球磨机均匀分散于环氧树脂涂料中以提高7A52铝合金表面有机涂层的耐腐蚀性能。通过接触角、吸水率、红外光谱、开路电位及交流阻抗测试,分别评价改性石墨烯环氧树脂涂层的表面润湿性、耐水性能、耐蚀性,并通过扫描电子显微镜对石墨烯粉末及环氧树脂涂层断面形貌进行分析。结果表明:环氧树脂涂料中添加0.8%改性石墨烯粉体后,接触角由86.77°增加至101.43°,提高16%,表面由亲水性变为疏水性,涂层的耐水性提高,吸水率降低0.21%。0.8%改性石墨烯涂层在3.5%NaCl溶液中稳定后的开路电位较未添加石墨烯涂层增加0.14 V,阻抗值高出未添加改性石墨烯涂层半个数量级,且电荷转移电阻R_ct比未添加改性石墨烯涂层R_ct高出1.78×10 ⁷ Ω/cm ²,涂层的耐腐蚀性大大提高。红外光谱表明,改性石墨烯并未改变环氧树脂结构,涂层中的改性石墨烯是影响涂层性能发生变化的重要因素。研究表明改性石墨烯的加入可以有效提高涂层的耐蚀性,并且当改性石墨烯添加量为0.8%时,涂层具有优异的耐腐蚀性能。

Effect of Modified Graphene on Corrosion Resistance of Epoxy Resin Coating

The modified graphene powder is dispersed in epoxy resin coatings to improve the corrosion resistance of organic coating on 7A52 aluminum alloy. The contact angle, water absorption test, infrared spectrum testing, open circuit potential tests and AC impedance tests are used to respectively evaluate the surface wettability, water resistance, corrosion resistance performance of graphene modified epoxy resin coating, and the scanning electron microscope is used to analyze the section morphology of the graphene powder and epoxy resin coating thereof. The results show that the addition of the modified graphene powder 0.8% increased the contact angle from 86.77° to 101.43° shifted from hydrophilicity to hydrophobicity, improved the water resistance and decreased water absorption by 0.21%. As compared to the unmodified coating, the open circuit potential of the modified coating was increased. The impedance value was increased by half order of magnitude. The R_ct was 1.78×10 ⁷ Ω/cm ² higher. The corrosion resistance was greatly increased. The infrared spectra showed that the modified graphene did not change the structure of epoxy resin. The improvement of the corrosion resistance of epoxy resin coating was due to the addition of modified graphene powder. The addition of modified graphene could effectively improve the corrosion resistance of the coating. When the amount of graphene was 0.8%, the coating had excellent corrosion resistance.