氨基化氧化石墨烯/磺化聚苯胺的制备及在水性环氧防腐涂料的应用

Preparation of amino-functionalized graphene oxide/sulfonated polyaniline and its application in waterborne epoxy anticorrosive coatings

以氯磺酸、苯胺和过硫酸铵为主要原料合成磺化聚苯胺(SPANI),用聚乙烯亚胺(PEI)还原氧化石墨烯(GO),合成氨基化氧化石墨烯复合材料(PG)。利用GO上活性位点,将SPANI与PG结合,制备了氨基化氧化石墨烯/磺化聚苯胺复合材料(SPG)。将SPG与水性环氧树脂共混制备了水性环氧防腐涂料。通过FTIR、XRD对SPG复合材料结构进行了表征。通过盐雾、电化学等实验对水性环氧涂层的防腐性能进行测定,并分析了涂层的物理性能。结果表明,PEI上的氨基成功与GO结合,SPANI成功增加了PG的层间距。添加2%SPG(以环氧树脂和水性环氧固化剂总质量为基准,下同)的水性环氧防腐涂层具有最优的耐腐蚀性,缓蚀效率可达99.19%,与纯水性环氧树脂(EP)相比,腐蚀电流密度从1080 nA/cm^(2)减小至307 nA/cm^(2),腐蚀电压从–0.840 mV升高至–0.347 mV。

Sulfonated polyaniline(SPANI)was synthesized from chlorosulfonic acid,aniline and ammonium persulfate.Amino-functionalized graphene oxide composite(PG)was obtained by reduction graphene oxide(GO)with polyethyleneimine(PEI).Amino-functionalized graphene oxide/sulfonated polyaniline composite(SPG)was prepared by combining SPANI with PG using the active site on GO.The waterborne epoxy anticorrosive coating was prepared by blending SPG with waterborne epoxy resin.The structure of SPG was characterized by FTIR and XRD.The corrosion resistance of waterborne epoxy coating was measured by salt spray and electrochemical experiments,and the physical properties of the coating were analyzed.The results showed that the amino group on PEI successfully combined with GO,and SPANI successfully increased the layer spacing of PG.The waterborne epoxy anticorrosive coating with2%SPG(based on the total mass of epoxy resin and waterborne epoxy curing agent,the same below)had the best corrosion resistance.The corrosion inhibition efficiency could reach 99.19%.Compared with those of pure waterborne epoxy resin(EP),the corrosion current density decreased from 1080 n A/cm^(2) to307 nA/cm^(2),and the corrosion voltage increased from–0.840 mV to–0.347 mV.