缓蚀型聚邻甲苯胺-氧化石墨烯基防腐材料的制备与性能

Preparation and properties of corrosion inhibited poly(o-toluidine)-graphene oxide-based anticorrosive materials

为开发缓蚀剂高效利用的新途径,选取氧化石墨烯为基材、聚邻甲苯胺微胶囊为壁材、缓蚀剂2-巯基苯并噻唑为芯材,制备了缓蚀型聚邻甲苯胺-氧化石墨烯基防腐材料,并将其作为填料用于水性环氧树脂涂层(WEP)的改性。通过FTIR、XRD、XPS和SEM等对材料进行了结构和形貌的表征,采用紫外可见光谱对缓蚀剂的释放行为进行分析,采用万能试验机、电化学测试和盐雾实验对涂层的拉伸性能和防腐性能进行了评价。结果表明:缓蚀剂成功包覆于聚邻甲苯胺微胶囊内部,并通过共价键方式将微胶囊连接在改性氧化石墨烯表面,使缓蚀剂得到了充分利用,提高了涂层的拉伸性能、自修复性能及对腐蚀介质的屏蔽性能。紫外可见光谱测试结果表明,微胶囊在人工破损96 h后,内部缓蚀剂的释放量达78%;拉伸性能测试结果表明,与纯WEP相比,当填料加入量为0.3wt%时,涂层应力从14.281 MPa增加到24.25 MPa;SEM结果表明,被划伤的涂层在常温下放置10 h后自修复;电化学测试和盐雾实验结果表明,涂层腐蚀电位从−0.6216 V提高到−0.1554 V,腐蚀电流密度从4.271×10^(−7)A·cm^(−2)减小到1.016×10^(−11)A·cm^(−2),阻抗模量可达到1.5757×10^(9)Ω·cm^(2),在盐雾500 h后仍表现出较好的防腐性能。

In order to develop a new way of efficient utilization of corrosion inhibitors,a corrosion inhibited poly(otoluidine)-graphene oxide-based anticorrosive materials was prepared by using graphene oxide as the substrate,poly(o-toluidine)microcapsules as the wall material and 2-mercaptobenzothiazole as the corrosion inhibitor as the core material,and it was used as the filler for the modification of waterborne epoxy resin coating(WEP).The structure and morphology of the coating were characterized by FTIR,XRD,XPS and SEM.The release behavior of the corrosion inhibitor was analyzed by UV-Vis spectroscopy.The tensile property and anti-corrosion properties of the coating were evaluated by universal testing machine,electrochemical test and salt spray test.The results show that the corrosion inhibitor is successfully coated inside poly(o-toluidine)microcapsules,and the microcapsules are connected to the surface of the modified graphene oxide by covalent bond,so that the corrosion inhibitor is fully utilized,and the tensile property,self-healing properties and shielding properties of the coating against corrosive media are improved.UV-vis spectrum test results show that the release of corrosion inhibitor in microcapsules reaches 78%after 96 h of artificial damage.The tensile property test results show that,compared with pure WEP,the coating stress increases from 14.281 MPa to 24.25 MPa when the filler content is 0.3wt%.SEM results show that the scratched coating self-healing after 10 h at room temperature.The electrochemical test and salt spray test results show that the corrosion potential of the coating increases from−0.6216 V to−0.1554 V,the corrosion current density decreases from 4.271×10^(−7)A·cm^(−2)to 1.016×10^(−11)A·cm^(−2),and the impedance modulus can reach 1.5757×10^(9)Ω·cm^(2).After 500 h of salt spray,the corrosion resistance is still good.