Designing Of The Phosphate Functional Monomer And Studying Its Application On The Modification Of Epoxy-based Anticorrosive Resin

Epoxy resin is a polymer matrix resin widely used in the field of coatings.The chain contains two or more epoxy groups.Through the ring-opening reaction of epoxy groups,the cross-linked cured coating forms a network structure,so that the cured coating has good corrosion resistance and physical and mechanical properties.At the same time,the coating has strong hydrogen bonding,intermolecular polarity and wet adhesion due to the combination of the coating and the metal substrate.In order to meet the needs of industrial anticorrosion and further improve the mechanical and corrosion resistance of epoxy-based anticorrosive resin,researchers often use it as matrix resin and modify it by means of chemical grafting and physical compounding in recent years.to achieve the purpose of optimizing the properties of epoxy-based anticorrosive resin system.Based on this,this topic through the design of a variety of phosphate functional monomers,in order to modify the traditional epoxy resin system,to achieve the purpose of improving the performance of epoxy resin substrate.The main contents of this thesis are as follows:1.A kind of diethyl phosphate(DPA)was designed to chemically modify the epoxy resin with different epoxy value.The phosphorous hydroxyl group of DPA was grafted with the epoxy group of epoxy resin to form epoxy phosphate.The results show that compared with pure epoxy resin,the modified epoxy phosphate not only improves the mechanical properties of the coating,but also binds to the metal surface,resulting in chelation and passivation of the metal surface.it provides the feasibility for its application in the field of metal anticorrosion.2.A kind of phosphate ester(HEMAPE)with hydroxyethyl methacrylate and ethoxy group was designed and synthesized,and it was used as an additive to modify acrylate epoxy ester by free radical polymerization,and its modification effect on matrix resin system was discussed.It was found that the stability and emulsifying performance of waterborne acrylate epoxy ester aqueous dispersion modified by HEMAPE were significantly improved,and the adhesion,surface hydrophobicity and anticorrosion properties of the coating to steel plate were significantly enhanced.The phosphate ion contained in the coating combines with the metal surface,resulting in chelation and passivation of the metal surface,which adheres to the surface of the metal substrate to inhibit the further occurrence of corrosion,thus optimizing the anti-corrosion performance of the coating.The design method is simple and easy and accords with the current concept of environmental protection,and has a considerable application prospect in the protection field of waterborne metal coatings.3.An epoxy-based emulsifier(PEG8000-E51)was designed to prepare waterborne epoxy dispersions by inversion.In order to further improve the properties of PEG8000-E51,hydroxyethyl methacrylate(HEMAPE)and castor oleic acid ethyl phosphate(ERP)were used as modifiers to modify waterborne epoxy emulsifier PEG8000-E51,and the modified emulsifiers HPG and EPG were synthesized.Epoxy resin was emulsified with modified emulsifier.Waterborne epoxy emulsions WHPG and WEPG were synthesized by reverse conversion,and their properties were compared.The results show that compared with pure waterborne epoxy aqueous dispersions,the use of ERP modified emulsifier EPG can further improve the stability,corrosion resistance and comprehensive mechanical properties of aqueous dispersions,which not only has a broad prospect in the field of epoxy emulsifiers,but also promotes the application of waterborne metal anticorrosive coatings.