Study On Polyaniline/Graphene Water-based Anti-corrosion Coatings And Their Properties

Outdoor steel structures are exposed to air for prolonged periods of time and are prone to electrochemical corrosion.In recent years,there are many commonly used anti-corrosion methods.Coating anti-corrosion is one of them.Water-based anti-corrosion coatings provide a new approach for corrosion protection of steel structures due to their environmental protection and low VOC emissions.However,the new type of water-based anti-corrosion coating has lower corrosion resistance than oil-based paint.In order to improve its corrosion resistance,this paper added graphene,polyaniline,polyaniline/graphene to prepare water-based anti-corrosion coating,making full use of the passivation and anodic protection of polyaniline,hydrophobicity and physical shielding of graphene improve the corrosion resistance of coatings.The corrosion resistance of the coating was characterized by immersion test,salt spray test and Tafel polarization curve.Using hydrochloric acid as doping acid and polyvinyl pyrrolidone as space stabilizer,polyaniline/graphene composites were prepared by in-situ polymerization method using aniline and graphene as raw materials and ammonium persulfate as oxidant.Adding graphene,polyaniline,polyaniline/graphene as fillers to waterborne alkyd to prepare anti-corrosion coating,through SEM,FI-TR,TG,immersion test,salt spray test,Tafel and so on,have the following results:（1）The optimum synthesis process of polyaniline/graphene:the reaction temperature is0℃,the reaction time is 6h,the amount of ethanol added is 80ml,PVP-K30:An is 20%.From the SEM image,polyaniline was uniformly covered on the sheet structure of graphene to form an oxidized intercalation layer structure,and the maximum loss point of polyaniline/graphene was 430℃,and the thermal stability was good.（2）When the graphene was added,the corrosion current of the coating with 0.4%addition was 0.7537μA·cm^-2,and when polyaniline was added,the corrosion corrosion current of the coating with 0.4%addition was 0.71694μA·cm^-2.When polyaniline/graphene was added,the corrosion corrosion current of the coating with 0.7%addition was 0.43098μA·cm^-2.（3）The addition of graphene,polyaniline,and polyaniline/graphene can increase the corrosion resistance of the coating.The improvement effect of polyaniline/graphene is the most obvious.When the addition amount of graphene/polyaniline is 0.7%of the total amount,the corrosion resistance of the coating is the best;when the addition amount of graphene is0.4%of the total amount,the coating resistance is The best corrosion resistance was obtained;when the addition amount of polyaniline was 0.4%of the total amount,the corrosion resistance of the coating was the best.The polyaniline/graphene anti-corrosion coating prepared in this paper not only has environmental protection,but also has good corrosion resistance,scratch resistance,and pitting resistance.The energy efficiency improves the corrosion of outdoor steel structures and prolongs the service life.