The Synthesis And Application Of Polyaniline And Graphene Nanosheets In Anti-corrosion Coatings

In recent years, with the rapid development of the economics, a large of steel，which easilysuffers corrosion，is used for transportation, construction, machinery, energy, chemical industry,infrastructure, railway and marine development and so on.The traditional organic anticorrosioncoating cannot meet the requirements, thus anti-corrosion coatings with more excellentperformance are needed.In order to reduce the holes and defects inthe traditional anti-corrosion coatingst,andincrease the anticorrosive properties, anticorrosive fillers, like polyaniline （PANI）,graphenenanosheets (GNS) and their mixtures were added into epoxy resin substrate, theanticorrosive performance of the coatings was investigated by means of the film thickness testing,adhesion tests immersion test, Tafel polarization curve test and so on.The fibrous PANI was prepared through controlled polymerization method, and then usedas anticorrosive filler for coatings.film thickness testing, adhesion tests, immersion test, Tafelpolarization curve and other characterization methods were used to research the anticorrosiveperformance of the coatings. It was investigated that the addition of PANI could promote theanticorrosive performance of the coatings effectively, and the anti-corrosive performance wasrelative with the amount of PANI. With the increase of the amount of PANI, the performanceincreases firstly and then decreases after reaching the optimum. The addition of PANI not onlypromote the adhesion and tightness of the coatings,but also provide electrochemicalanticorrosion due to its high conductivity and easy reduction–oxidation. GNS was prepared bythe reduction of graphene oxide (GO), and then was added into epoxy resin substrate to prepareanticorrosive coatings. The coatings with different content of GNS (0.5%~2%) were prepared,and film thickness testing, adhesion tests, immersion test and tafel polarization curve were usedto investigate the anticorrosive performance of the coatings. It was investigated that with theincrease of GNS content, the anticorrosive performance of the coatings increase firstly and thendecrease, reach the maximum at content of1%. The excellent anticorrosive performance ofgraphene results from the good conductivity, hydrophobic property and unique two dimensionalstructure.Finally, mixture of PANI and GNS(1:9,2:8,3:7) was added as anticorrosive fillers into theepoxy resin substrate. The anticorrosive performance of the coatings was relative to the contentof GNS, the more the GNS in the coatings, the better was the anticorrosive performance of the coatings.