Preparation And Anticorrosive Performance Of Covalently Functionalized Nanoparticles/Polyaniline Anticorrosion Coating

Polyaniline has been widely applied in the field of metal anti-corrosion due to the great electrical conductivity,unique doping-dedoping process,unique pitting corrosion resist and great environmental stability.In this paper,a series of covalent functional inorganic particles/polyaniline-based anticorrosive coating materials were prepared,and the anticorrosive properties of the prepared coatings were studied.The main contents are as follows:（1）Aminosilsesquioxane（POSS）was synthesized by hydrolytic condensation of silane coupling agentΓ-aminopropyltriethoxysilane（KH550）.Aminosilsesquioxane/sulfonated polyaniline composites were prepared by grafting polymerization of sulfonated polyaniline（SPANI）and POSS on the surface of POSS.Finally,a covalently functionalizetion octaaminosilsesquioxane/polydimethylsiloxane（POSS/PDMS）anticorrosive composite coating was prepared.Scanning electron microscopy（SEM）showed that the surface morphology of the composites was regular,with granular and short fibers.The composite coating has the best hydrophobicity and the contact angle reaches 115°.The composite coating has better anticorrosion effect on carbon steel,and its corrosion potential is about 70m V higher than the PANI/PDMS coating.In addition,it is also found that the larger the contact angle of the coating,the better the corrosion resistance become.（2）Polyaniline covalently functionalized POSS was doped with two kinds of phosphoric acid（phosphoric acid and 2-hydroxyphosphonic acid（HPAA））to prepare composite materials based on the unique doping and dedoping characteristics of polyaniline,and two kinds of epoxy anticorrosive composite coatings were prepared.The results showed that the epoxy composite coatings with 1%H₃PO₄-PANI-POSS and 1%HPAA-PANI-POSS had the maximum polarization resistance R_p and the best corrosion resistance in corrosion test of coatings with different contents.The anti-corrosion performance of H₃PO₄-PANI-POSS epoxy composite coating is better than others,which indicates that the anticorrosion effect of inorganic acid doped polyaniline composite coating is stronger than the organic acid doped polyaniline composite coating.The H₃PO₄-PANI-POSS composite coating has better corrosion resistance with the increase of immersion time.（3）The corrosion resistance of the composite coating was studied by changed inorganic particles.The covalently functionalized Si C-NH₂-SPANI composite was synthesized by one-step oxidative polymerization using aniline,aminobenzene sulfonic acid and self-made amino Si C nanoparticles as raw materials,and finally the epoxy composite coating was prepared.The results of hydrophobic property show that the contact angle value of the composite coating with 3%Si C-NH₂-SPANI reaches 99.87°,which is higher than that of the composite coating that used the pristine Si C substituted for Si C-NH₂.With regard to the corrosion resistance of Si C-NH₂-SPANI/EP composite coating,it was found that when the mass fraction of Si C-NH₂ was 15%,the best performance of Si C-NH₂-SPANI was obtained when the molar ratio of ammonium persulfate and amino monomers（aniline and aminobenzenesulfonic acid was 1:1）was 1:1.Among the composite coatings doped with different materials（Si C/EP,Si C-NH₂/EP and Si C-NH₂-SPANI/EP）,the Si C-NH₂-SPANI/EP composite coating has the largest contact angle,the best hydrophobic performance and anti-corrosion performance.It also shows that there is a relationship between hydrophobic property and anticorrosion property and the hydrophobic performance is directly proportional to anticorrosive performance.With regard to the influence of the content of composite coatings,the long-term stability and corrosion resistance are more excellent when the addition of Si C-NH₂-SPANI/EP is 3%.