三聚磷酸铝/氧化石墨烯复合材料在水性防腐涂料中的应用

Application of Aluminum Triphosphate/Graphene Oxide Nanocomposite in Waterborne Anticorrosive Coatings

采用球磨分散法制备得到三聚磷酸铝/氧化石墨烯水性复合防腐浆料(AlTP/GO),并与水性环氧树脂复配制得纳米复合防腐涂料(EP-AlTP/GO)。通过场发射扫描电镜(FE-SEM)观测到AlTP/GO可均勻分散到EP树脂内部。吸水率测试结果表明,氧化石墨烯的引人提高了涂层的耐水性和屏蔽性能;附着强度测试结果表明,三聚磷酸铝可提高涂层在金属基材上的附着强度;电化学测试(Bode)和环境扫描电镜测试(E-SEM)结果表明,AlTP/G0可有效增强水性环氧涂层对腐蚀介质的屏蔽作用,限制了腐蚀反应的扩散,在3.5%NaCl水溶液中浸泡40d后其低频阻抗达到7.02×10^7Ω·cm^2,盐雾测试400h后金属表面平滑,金属腐蚀未发生明显扩散,EP-AlTP/GO人工破损处周边含氧量低至15.66%,遏制了氧化铁的形成。

The water-based aluminum triphosphate / graphene oxide composite anticorrosion pigment millhase was prepared by ball-mill dispersion and then was formulated with a water-based epoxy resin to prepare EP- AlTP/GO nanocomposite coatings. The AlTP/GO could be evenly dispersed into EP resin which was observed by field emission scanning electron microscopy (FE-SEM). The water absorption test showed that the incorporation of graphene oxide improved the water resistance and barrierperformance of the coatings. The adhesion test results showed that aluminum triphosphate could improve the adhesion of the coatings on metal substrates. Electrochemical test (Bode) and environmental scanning electron microscopy test (E-SEM) showed that AlTP/GO effectively enhanced the barrier performance of water-based epoxy coatings to corrosion medium and limited the spreading of the corrosion reaction. The low frequency impedance was 7.02×10^7Ω·cm^2 after immersion at 3.5 wt.%NaCl aqueous solution for 40 days, the metal surface remained smooth after sail spray test 400 h. EDX test showed that AlTP/GO could inhibitthe formation of iron oxide, the oxygen content around the damaged area of EP- AlTP/GO was as low as 15.66%.