Preparation And Properties Of Organic-inorganic Hybrid Superhydrophobic Epoxy Anti-corrosion Coating

Because of the excellent mechanical properties,electrical properties,adhesive properties,heat resistance,solvent resistance,easy molding and processing,and low cost,epoxy resin is widely used in plastics,coatings,machinery,chemical industry,national defense and many other fields.However,pure epoxy resin is brittle and prone to cracking,and has poor impact and corrosion resistance,limiting its application in certain high-tech fields.With the rapid rise of organic-inorganic hybridization technology,and the excellent thermal stability,oxidation resistance,water repellency and weathering resistance of polysiloxane,many researchers have focused on combining the two to produce organic-inorganic hybrid coatings with excellent performance.In view of this,in this paper,mesoporous molecular sieves loaded corrosion inhibitors were added to pure epoxy resin coatings to produce organic-inorganic hybrid epoxy coatings(Inh@MS-EP).Mesoporous molecular sieves loaded corrosion inhibitors were added to epoxy resin modified by amino silicone oil to produce polysiloxane modified hybrid hydrophobic coatings(Inh@MS-NEP).Superhydrophobic surface construction was carried out on the surface of Inh@MS-NEP coatings to prepare polysiloxane-modified organic-inorganic hybrid superhydrophobic coatings(Inh@MS-SNEP).The hydrophobic properties of various coatings as well as the corrosion protection properties were investigated.The main studies are as follows.(1)Inh@MS-EP coating was produced by adding mesoporous molecular sieves loaded triazine corrosion inhibitor into pure epoxy resin.The modified molecular sieve was confirmed by FT-IR method,and the optimum loading concentration and loading amount of the corrosion inhibitor was determined by TG.The effect of the addition of modified molecular sieve on the hydrophobic and anticorrosive properties of the coating were investigated by means of contact angle measurements and electrochemical tests.The results showed that the highest molecular sieve loading was achieved at a concentration of 35 g/L of triazine corrosion inhibitor,with a maximum loading of 25.91%.With the addition of modified molecular sieves,the water contact angle increased from 40°to 100.9°,and the corrosion resistance of the coating improved.|Z|_{0.01 Hz}increased to 1.47×10~7?·cm~2,a 17 times increase over the 8.52×10~5?·cm~2of the pure EP coating when the modified molecular sieve was added at 5 wt.%.(2)In order to improve the hydrophobicity of organic-inorganic hybrid coatings,Inh@MS-NEP was prepared by grafting epoxy resin with amino silicone oil.The effect of the addition of amino silicone oil on the hydrophobic and anti-corrosion properties of the coatings were investigated by means of contact angle measurement,electrochemical tests and salt spray tests.The physical properties of Inh@MS-NEP coatings were tested for adhesion,hardness and impact resistance.The results showed that the water contact angle could reach125.9°at 15 wt.%of amino silicone oil addition,and|Z|_{0.01 Hz}increased to 1.76×10~8?·cm~2.The salt spray test and corrosion immersion test proved that the Inh@MS-NEP coating possessed better anti-corrosion properties,and the mechanical properties such as adhesion,hardness and impact resistance were significantly improved.(3)In order to further improve the hydrophobic and anticorrosive properties of the coating,a superhydrophobic layer with micro-nano roughness was constructed on the surface of the Inh@MS-NEP coating to produce the Inh@MS-SNEP superhydrophobic coating.The measured water contact angle of the Inh@MS-SNEP coating was 169.3°and the rolling angle was less than 1°.Although,the coating was not very different from Inh@MS-NEP coating in short-term corrosion protection,but Inh@MS-SNEP coating exhibited better performance on long term corrosion protection.The mechanical properties of the Inh@MS-SNEP coating were slightly lower than those of the Inh@MS-NEP coating,but still better than those of the pure epoxy resin coating.The Inh@MS-SNEP coating has a contact angle of over 150°and a rolling angle of less than 10°after 15 abrasive rubbings or 6 h immersion in strong acid and alkaline solutions,and had a good self-cleaning capacity.