Study On The Preparation And Anticorrosion Of Epoxy Resin Coating Modified By Polyaniline

The material and technology of traditional coating usually cannot achieve ideal effect of corrosion prevention. Meanwhile quite a number of coatings with toxic substance will cause environmental pollution during preparation and use. Therefore it is an urgent affair to develop the coating which is environment friendly and high efficient. As a newly developing conductive macromolecule, polyaniline has many advantages such as simple structure, moderate price, superstrong stability and so on. Especially to be used as the anti-corrosion coting, polyaniline is brought to the forefront for its excellent performance and it will be the most promising material in the anti-corrosion area.At first, EB was synthesized through the chemical oxidation method. Then m-cresol was chosen as the menstruum,and the epoxy resin was chosen as the base material according to some standards. The anticorrosion coatings of DBSA-PANI/epoxy resin, PANI/epoxy resin and H3PO4-PANI/epoxy resin were prepared according to certain formula and spreaded on steel surface. The influences of soak time,contents of PANI-DBSA,EB and H3PO4-PANI, corrosive medium and the ability of repassivation of the samples were investigated by Tafel plots in the presence of lmol/L HCl and3.5%NaCl solutions after coating were harded,adhesion was tested by inscripting cycles.Conclusions as following:1Because of the epoxy resin, the adhesion are preferable. The adhesion of all the samples reached grade2.2The anti-corrosion effect of the three kinds of coatings are changing with time. Generally the trend is that the samples anticorrosive effect are ascending and have the effect on corrosion with the passivation effect became more and more exposed.The anticorrosive effect of1%EB and1%DBSA-PANI are better than0.33%ones.But the H3PO4-PANI is different and it’s0.33%H3PO4-PANI is better.DBSA-PANI/epoxy resin has the minimum corrosion current so it has the best passivation effect than the other ones.3Polyaniline coating has the ability of passivation. It can repair the coating twice when the coating is destroyed. When the part of the destruction is big it has a great impact on the samples which are soaked in the3.5%NaCl and it has not so great impact on the samples which are soaked in the1mol/LHCl.