Preparation,Characterization Of PANI And PANI Modified Basalt Plate/Epoxy Coatings

Corrosion of metals can induce tremendous economic loss and a serious human life disaster.While,corrosion cannot be fully eliminated,but can be controlled which mainly by slow its corrosion rate and/or altering its mechanism.The most common and cost effective way to protect metals from corrosion is employing organic coatings.However,ordinary organic coatings cannot meet the requirement of heavy-duty corrosion environment.Therefore,conduct-polymers and inorganic additives were used as additives to improve the coating's passivation and barrier properties.In this thesis,PMBs were successfully prepared by chemical oxidation polymerized aniline in the presence of basalt micro-platelets.FTIR,TGA and SEM characterization revealed that PANI was uniformly and tightly attached to the basalt micro-platelets.Protective performance of the PMB coatings was investigated by immersion them in 12wt%NaCl solution at 95^oC for 80 days and characterized by electrochemical impedance spectroscopy.The experimental results demonstrate that EPMBII coating show extremely higher protective performance than that of other coatings.Besides,PMBs have positively affected the thermal properties,water repellency and adhesion strength of the epoxy resins.The SEM and XPS results demonstrate that polyaniline can facilitate the formation of dense iron oxide layer?Fe₂O₃/Fe₃O₄?at the interface of coating and substrate.To investigate the delamination behavior of PANI incooperated epoxy coatings,epoxy coating containing 0,1%,2%,3%PANI were prepared and immersed in12%NaCl,5%HCl,5%NaOH at different temperature,respectively.Solutions and coating films after immersing were test by UV-vis and SEM for a certain intervals.UV-vis and SEM tests results indicated that both PANI and epoxy films delaminated in 12%NaCl solution.However,there was no obvious degradation of PANI in NaCl solution,while has serious delamination in 5%HCl solution.PANI and epoxy films also degraded in 5%NaOH solution.The degradation products differ in different solutions.EIS results showed that an appropriate content of PANI can improve the protection performance of epoxy coatings in 12%NaCl,5%HCl,5%NaOH solutions through the passivation ability of PANI.