Green Synthesis Of Nano-modified Epoxy-acrylate Emulsion And Its Application In Anticorrosive Coatings

With the rapid development of nano-science and technology,especially in the field of anti-corrosion coatings,the development of new nano-modified coatings has become a new trend in the field of coatings.In this topic,a semi-continuous seed emulsion polymerization method was used to prepare epoxy acrylate soap-free core-shell emulsion.The nano-SiO₂ and GO were used to modify the epoxy acrylate emulsion to prepare the nano-modified epoxy acrylate composite coating.The specific research contents are as follows:?1?Select butyl acrylate as the dispersion medium of epoxy resin to prepare epoxy acrylate,use it as the core monomer,select styrene as the shell monomer,epoxy acrylate without soap core-shell emulsion is synthesized,by using semi-continuous seed emulsion polymerization method.When the optimal temperature of monomer drop is 45°C,the optimal temperature for emulsion polymerization is 70°C,the core-shell ratio is 1:1.2,and the optimal amount of water is 1.8 times the polymerization monomer,the monomer conversion rate of the emulsion can reach 98.46%.The prepared emulsion has good mechanical stability,chemical resistance and electrolyte resistance,and is characterized by infrared spectroscopy?FT-IR?and nuclear magnetic resonance ¹³C spectroscopy.The TEM results show that the synthesized emulsion has obvious nuclear core-shell structure.?2?On the basis of St?ber method,with the evaluation indicators of conversion rate and particle size,the optimum experimental conditions for the preparation of Nano-SiO₂particles were determined by orthogonal test.The conversion rate of TEOS reached about99.93%,and the average particle size of the prepared Nano-silica particles was 159.8nm.The Nano-SiO₂ was modified by KH-550,and was characterized by FT-IR and SEM.Under the best conditions,select different proportions of methyl orthosilicate?TMOS?and ethyl orthosilicate?TEOS?to prepare modified Nano-silica.Dispersing Nano-silica as anticorrosive pigment in epoxy acrylate without soap core-shell emulsion,the prepared Nano-silica/epoxy acrylate composite coating had better mechanical properties,when the TEOS:TMOS of the composite silicon source for preparing Nano-silica is 1:1.After480h salt spray resistance test,the coating is only slightly rusted at the scribe line and there is no blistering on the surface of the coating;At the same time,immersed in 3.5%NaCl solution for 600h,the low-frequency AC impedance value of coating was 1.18×10⁶?·cm²,showing the best anti-corrosion performance.?3?Graphene oxide?GO?is prepared by the Hummer method,and the rich oxygen-containing groups on the surface of graphene oxide are used as reactive sites,Modified GO water dispersion is obtained by grafting KH-550 onto graphene oxide.The structure of GO was characterized by FT-IR,XRD and TEM.Graphene has good dispersibility in the resin and the prepared GO/epoxy acrylate composite coating had better mechanical properties,when the graphene content is 2w%.The corrosion resistance is the strongest in the 480h neutral salt spray test.In the electrochemical test,the coating has not failed after immersion in a 3.5%NaCl solution for 600h.The low-frequency AC impedance value is 1.21×10⁶?·cm²,which shows the best corrosion resistance.