Application Of PANI/Zinc Powder In Anticorrosive Coatings By Coupling Agent

Polyaniline(PANI)and zinc powder are often used as antiseptic coatings.PANI is widely used in anticorrosive coatings because of its high conductivity,unique doping mechanism,cheap raw materials and simple preparation methods.However,PANI dissolves and poor machinability,In the water-based anti-corrosion coating dispersion performance is not good,so how to solve PANI in the water-based system dispersion performance is the current main research direction.In this paper,different types of silane coupling agent are used to process PANI,to improved PANI dispersion performance.Zinc powder in the oily coating dispersion performance is poor,under the surface repair of titanate coupling agent,the performance of zinc powder was improved,in addition to the role of PANI to enhance the anti-corrosion properties of the coating.Synthesis of doped polyaniline by using ammoni?m persulfate as oxidant,hydrochloric acid,hydrofluoric acid,dodecylbenzene sulfonic acid and citric acid as doped acid.The PANI was studied by means of FTIR,TG,conductivity and SEM.The PANI was processed by different hydrolysed silane coupling agents(Anilino-methyl-triethoxysilane(ND-42),3-Aminopropyltriethoxysilane(KH-550),Glycidoxypropyltrimethoxysilan(KH-560)and 3-Methacryloxypropyltrimethoxysilane(KH-570)respectively)with different conditions to improve their ability to disperse.The FTIR spectr?m of PANI pretreatment indicated that the silane coupling agents were doped successfully on the PANI.The particle size analysis showed that the PANI particle size increased after pretreatment and the unit mass sedimentation vol?me of the PANI processed by ND-42 was 0.3 mL/g,which decreased 83.3%compared with the unprocessed PANI.PANI was added to the aqueous epoxy coating to prepare the coating and then tested for mechanical properties.The results show that the adhesion,hardness and impact resistance of the coating are improved in different degree.Among them,the corrosion potential of ND-42 modified PANI coating was-0.484 V,which was shifted by 0.14 V compared with the PANI coating without coupling agent and the corrosion current density decreased by 54.9%,in addition to this,No significant rusting occurred after 120 h of salt spray.The oily epoxy anti-corrosion coating system was established,then the zinc powder was modified by titanate coupling agent and compounded with PANI.Next examine the effects of different types of PANI on oily systems under different usage.Among them,we found that the pHysical and mechanical properties of the 42-PANI/Zn coating and the HCl-PANI/Zn coating were not significantly different.The addition of PANI enhances the corrosion resistance of zinc powder system.When the amount of PANI is 1%,the corrosion resistance is the most significant and the corrosion voltage is-0.077V.