Study On The Preparation And Anticorrosion Of Polyaniline

The anticorrosion of the traditional coatings to metal is not ideal due to their material properties and technology.And a lot of the coatings contain poisonous matters that induce the environment polluted.The development of new green coatings becomes one of targets of the corrosion protect field. Polyaniline becomes a focus of research due to low cost,simple synthesis,high chemical and environmental stability.Polyaniline is emphasized as a kind of perfect anticorrosion material and most probably applied in anticorrosion field.At first,polyaniline(PANI)doped by dodecylbenzene sulfonate acid(DBSA) and emeraldine were synthesized by the chemical oxidation way,separately. And they were characterized by FTIR.Then the proper solvent which can dissolve PANI and base material which is of high adhesion were chose.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 Q235 steel surface.The influences of time,contents of PANI-DBSA,EB and H₃PO₄-PANI,and media on the anticorrosion properties of Q235 steel samples were investigated by Tafel plots in the presence of 3.5% NaCl and 1 mol/L HCl solutions after coatings were hardened,adhesion was tested by inscripting cycles.The results showed that the anticorrosion of samples coated by DBSA-PANI/epoxy resin,EB/epoxy resin and H₃PO₄-PANI/epoxy resin was improved with the passage of time;the anticorrosion of samples coated by above three coatings separately containing 1%DBSA-PANI,EB and H₃PO₄-PANI was better than 0.33%;of the three kinds of samples,except sample coated by coatings containing 1%DBSA-PANI,EB and H₃PO₄-PANI,the anticorrosion of the others in 3.5%NaCl solutions was higher than in 1 mol/L HCl solutions.In addition,samples were of some anticorrosion both in 3.5%NaCl solutions and 1 mol/1 HCl solutions,and anticorrosion reached above grade 7 according to 10 grades standard;above grade 2 according to 3 grade standard,the anticorrosion of samples coated by coatings containing PANI was better than the others. Moreover,adhesion of all samples reached grade 2.