Preparation And Research Of Anticorrosive Coatings Filled With Layered Materials

Waterborne epoxy resin(EP)coatings have been widely used because of their excellent performance and environmental protection characteristics.But at present,there are many problems in waterborne anticorrosive coatings,such as voids formed by water volatilization,weak barrier and short anticorrosive period of coatings.In order to solve this problem,most of the current methods are to add nano-inorganic fillers to the resin to plug the hole.Among them,the blocking ability of layered materials is the best.Graphene oxide has a layered structure similar to graphene,and a large number of hydroxyl and carboxyl groups on its surface are easy to modify.However,it is because of the existence of these functional groups that they are easy to form hydrogen bonds and agglomerate,which leads to the degradation of their performance in application.In order to solve this problem,sodium tripolyphosphate was used to modify graphene oxide to weaken hydrogen bond and improve agglomeration.Moreover,sodium tripolyphosphate can chelate with metal to form passive film to protect metal,which can be used to improve the corrosion resistance of the coating.The synthesized product was proved to be successful by infrared spectroscopy(IR),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).The improvement of agglomeration was proved by digital photographs and scanning electron microscopy(SEM).Adding Modified Graphite Oxide to Coatings to Test the Properties of Coatings.The corrosion resistance and mechanical properties of the coatings were characterized by electrochemical impedance spectroscopy(EIS),salt spray test and adhesion test.When the mass fraction of graphene oxide modified by sodium tripolyphosphate is 0.7%,the mechanical properties and corrosion resistance of the coating are the best.In addition,this paper also adopts the physical combination method,doping nanocellulose into graphene oxide,reducing the accumulation of graphene oxide,thus improving the agglomeration of graphene oxide.The success of doping and the improvement of agglomeration were proved by infrared spectroscopy(IR),thermogravimetric analysis(TGA),X-ray diffraction(XRD),scanning electron microscopy(SEM)and digital photographs.The corrosion resistance and mechanical properties of the coating were characterized by electrochemical impedance spectroscopy(EIS),salt spray test and adhesion test.When the mass fraction of nanocellulose doped graphite oxide was 0.7%,the mechanical and corrosion resistance of the coating was the best.Hydrotalcite,nicknamed layered bimetallic hydroxides,has a unique layered structure.Because of its high metal dispersion,it has certain application in coatings with metal substrates.The anion exchangeability between layers provides diversity for its modification.In this paper,sodium tripolyphosphate pillared hydrotalcite was used to improve the corrosion resistance of the coating by utilizing the layered structure of the hydrotalcite and the characteristics of ion exchange(absorbing corrosion ions and replacing tripolyphosphate ions which protect the metal matrix).Through different characterization methods and experimental data,detailed demonstration is made.The intercalation was proved to be successful by infrared spectroscopy(IR),thermogravimetric analysis(TGA),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The electrochemical impedance spectroscopy(EIS)and salt spray test showed that the coating had the best corrosion resistance when the mass fraction of sodium tripolyphosphate intercalated hydrotalcite was 1.0%.