氟化石墨烯硅烷功能化对环氧复合涂层耐腐蚀性的影响

Effect of Fluorinated Graphene Silane Functionalization on the Corrosion Resistance of Epoxy Composite Coatings

采用γ-缩水甘油醚氧丙基三甲氧基硅烷(GPTMS)对氟化石墨烯(FG)进行功能化处理得硅烷功能化氟化石墨烯(GFG),采用XRD、FT-IR和SEM对粉体进行表征;将FG和GFG分别加入环氧树脂中获得复合涂层,通过电化学测试和5%NaCl中性盐雾试验研究复合涂层的耐腐蚀性。结果表明:FG能有效地增加环氧涂层(EP)的长期耐腐蚀性,FG经过硅烷功能化处理后进一步提升了其与树脂之间的界面相容性,所得复合涂层的致密性进一步提高,从而显著提升了环氧复合涂层的耐腐蚀性。经3.5%NaCl溶液4000 h浸泡后,GFG改性环氧复合涂层(GFG/EP)的低频阻抗模值相较于纯EP涂层提升了3个数量级,较FG改性环氧复合涂层(FG/EP)提高了1个数量级;同时盐雾腐蚀90 d后,GFG/EP涂层表面无明显腐蚀现象。

The fluorinated graphene(FG)was functionalised withγ-glycidyl ether oxypropyl trimethoxysilane(GPTMS)and the powders were characterised by XRD,FT-IR and SEM;the FG was added to epoxy resin before and after silane functionalisation to obtain the composite coating,and the corrosion resistance of the composite coatings was investigated by electrochemical methods and 5%NaCl neutral salt spray tests.The results showed that FG could effectively increase the long-term corrosion resistance of the epoxy coating(EP),and the silane-functionalised graphene fluoride further improved the interfacial compatibility between it and the resin,and the denseness of the resulting composite coating was further improved,thus significantly enhancing the corrosion resistance of the epoxy composite coating.After soaking in 3.5%NaCl solution for 4000 h,the low frequency impedance modulus of the silane-functionalised graphene fluoride modified epoxy composite coating(GFG/EP)was increased by 3 orders of magnitude compared to the pure EP coating and by 1 order of magnitude compared to the ordinary graphene fluoride modified epoxy composite coating(FG/EP).After 90 days of salt spray corrosion,the surface of the GFG/EP coating showed no significant corrosion.