氧化石墨烯改性环氧隔热涂层的耐蚀和隔热性能研究

用氧化石墨烯(GO)浓缩浆分散法制备GO改性环氧隔热涂层,在浓度(质量分数)为3.5%的NaCl溶液(50℃)中进行腐蚀实验并测试其腐蚀前后的隔热性能。432 h的腐蚀电化学测试结果表明,用0.5%(质量分数)的GO改性显著提高了涂层低频阻抗,涂层的耐蚀性优于无GO改性和1.0%GO改性的涂层;SEM分析结果表明,用0.5%和1.0%GO改性的隔热涂层腐蚀432 h后表面形貌完好,涂层/基体界面处没有出现裂纹和腐蚀产物,而未经GO改性的涂层出现了明显腐蚀破坏。腐蚀试验前,0.5%、1.0%GO改性的涂层与没有改性的涂层的隔热性能没有明显的区别;腐蚀432 h后涂层对250℃热源分别降温98℃、123℃、115℃,粘结强度分别降低了3.9、1.0、2.3 MPa。实验结果表明,用0.5%GO改性的涂层耐蚀和隔热性能最好。

Study on Corrosion Resistance and Thermal Insulation Properties of Graphene Oxide Modified Epoxy Thermal Insulation Coating

Graphene oxide (GO) modified epoxy thermal insulation coatings were prepared by adding GO concentrates, then corrosion immersion test in 3.5%NaCl (mass fraction) solution at 50^oC and thermal insulation effect before and after corrosion tests were comparatively measured. Electrochemical analysis shows that the coating modified with 0.5% GO has higher low-frequency resistance than that of coatings with 0% and 1.0% GO. Good surface morphologies were retained for coatings with GO addition after immersion in 3.5% NaCl solution (50^oC) for 432 h. Meanwhile, no obvious cracks and corrosion products were detected on the coating/substrate interface. The coating without GO addition emerges obvious corrosion. The thermal insulation effect to a 250^oC heat source of the above three coatings before corrosion test presents slight differences. Whereas, after 432 h corrosion immersion test the coating with 0% GO, 0.5% GO and 1.0% GO presents quite different in thermal insulation effect with temperature drop as 98^oC, 123^oC and 115^oC for the coated substrate and decrease of bonding strength to the substrate as 3.9 MPa, 1.0 MPa, 2.3 MPa respectively. These results verify that the epoxy coating modified with 0.5% GO has the best corrosion resistance and thermal insulation performance.