Study On Controllable Preparation Andanti-corrosion Performance Of Polyaniline Modified Molybdenum Sulfide/Epoxy Composite Coating

Severe corrosion of metals always leads to increased structural damage and huge economic losses in various industries.Severe metal corrosion can also cause casualties and hinder the development of science and technology and production.Therefore,it is of great significance to take reasonable and effective protective measures to slow down the corrosion rate of materials.The organic coating method is the most widely used,economical and effective anti-corrosion method.Epoxy coatings have been widely used in corrosion protection coatings for corrosive media due to their excellent chemical resistance,adhesion,and excellent resistance to mechanical and friction strength.PANI,as a conductive polymer material,is more and more researched on the basis and application of anti-corrosion coatings.Due to the poor solubility of PANI,its own porosity and low adhesion,it must be compounded with other components to achieve the desired anti-corrosion effect.The protective performance of the coating also depends on its barrier and shielding effects on H₂O,O²,Na⁺,Cl^-,SO₄^2-,etc.and on corrosion inhibition,among which fillers play a vital role.In recent years,the role of graphene two-dimensional material modifiers in organic coatings has attracted much attention.Using its two-dimensional sheet structure to superimpose layers in the coating,it can form small-molecule corrosive media(water molecules,chloride ions,etc.).The hard-to-pass dense isolation layer plays a prominent physical isolation role.Based on the introduction of MoS₂nanosheets as a barrier agent,this article uses PANI to modify MoS₂ to form PANI@MoS₂ nanoparticles.In this article,different methods are used to modify nanomaterials to obtain epoxy composite coatings with excellent anticorrosive properties.The specific research content and conclusions of this paper are as follows:(1)Using PANI to modify MoS₂,i-PANI@MoS₂ nanoparticles and g-PANI@MoS₂ nanoparticles were prepared by in-situ polymerization and exfoliation methods.Among them,the surface of the MoS₂ sheet of i-PANI@MoS₂-7 and g-PANI@MoS₂-5 is completely covered by PANI,and the size and dispersion of nanoparticles are uniform,and the modification effect is the best.The conductivity of i-PANI@MoS₂-7 nanoparticles reaches 0.765S/cm,and the intercalation of Li+and PANI makes the conductivity of g-PANI/MoS₂ nanoparticles higher than that of i-PANI@MoS₂,g-PANI/MoS₂-5 reached 1.486S/cm.(2)Add i-PANI@MoS₂ nanoparticles to epoxy resin to prepare an EP with excellent anti-corrosion properties.i-PANI@MoS₂-7 is evenly dispersed in the epoxy resin matrix,indicating that the uniform loading of PANI will facilitate the dispersion of MoS₂ in EP.With the increase of PANI ratio,i-PANI@MoS₂-7/EP has the largest resistance value of 4.66×10⁴?·cm²,the maximum corrosion voltage-0.110V,and the smallest corrosion current density of 2.06×10^-7A·cm2,Excellent anti-corrosion performance.With the increase of the content of i-PANI@MoS₂-7,8%i-PANI@MoS₂-7/EP has the best conductivity and barrier performance and the largest contact angle;8%i-PANI@MoS₂-7/EP has The maximum resistance value is5.52×10⁴?·cm²,the maximum corrosion voltage is-0.131V,and the minimum corrosion current density is 1.71×10^-7A·cm²,showing the most excellent anti-corrosion performance;the crosslinking density of EP coating decreases,the system The rigidity decreases,so the initial storage modulus of the EP coating decreases.The addition of i-PANI@MoS₂-7 can increase the carbon residue rate of the EP coating,and at the same time form a thermal conductivity network,so that the coating is heated evenly,and it is not prone to local heat storage and degradation.(3)g-PANI@MoS₂ nanoparticles are added with epoxy resin to prepare an EP with excellent anti-corrosion properties.The g-PANI@MoS₂-5 nanoparticles are uniformly dispersed in the epoxy resin matrix,indicating that the uniform loading of PANI will facilitate the dispersion of MoS₂ in EP.With the increase of PANI ratio,g-PANI@MoS₂-5/EP has the largest resistance value of 4.76×10⁴?·cm²,the maximum corrosion voltage of-0.091V,and the smallest corrosion current density of2.56×10^-6A·cm²,Excellent corrosion resistance.With the increase of g-PANI@MoS₂-5content,8%g-PANI@MoS₂-5/EP has the best conductivity and barrier performance,and the contact angle is the largest;8%g-PANI@MoS₂-5/EP has The maximum resistance value is 5.75×10⁴?·cm²,the maximum corrosion voltage is-0.134V,and the minimum corrosion current density is 2.98×10^-10A·cm²,showing the most excellent anti-corrosion performance;the crosslinking density of EP coating decreases,and the system is rigid Decrease,so the initial storage modulus of the EP coating decreases.The addition of g-PANI@MoS₂-5 can increase the carbon residue rate of the EP coating,and at the same time form a thermal conductivity network,so that the coating is evenly heated,and it is not prone to local heat storage and degradation.When the addition amount is the same,g-PANI@MoS₂-5/EP i-PANI@MoS₂-7/EP has better corrosion resistance.