Preparation And Properties Of Aqueous Graphene Oxide/Epoxy Resin Emulsion

Anticorrosive coating is one of the most important applications of epoxy resin(EP).Compared with solvent-based coatings,the water-based epoxy coatings are friendlier to human health and the environment,however,there are also some questions on stability and anticorrosive performance of water-based epoxy coatings.Therefore,it is still a challenge to improve the stability and corrosion resistance of waterborne epoxy coatings.Nowadays the functional fillers,such as graphene and graphene oxide(GO),due to their excellent properties,have been applied in the field of anticorrosive coatings.In this work,the water-based epoxy(EP)emulsion and GO/EP composite emulsion containing GO with different oxygen contents were prepared successfully,on the base of technology of hydrophilic epoxy surfactant(EEO)prepared with epoxy resin E-51 and poly(ethylene glycol)as emulsifier.The pure epoxy emulsion,GO,the composite GO/EP emulsion and the emulsion films were characterized respectively and the optimal conditions of stable epoxy emulsion was obtained.The storage stability of the emulsion can arrive at one year under optimum conditions(EEO content is 15%(weight ratio to epoxy resin),the agitation speed is 2000 min^-1 and time is one hour).The composite emulsion modified by GO-3 showed the best anti-corrosion performance.In addition,we found that the annual corrosion rate were reduced by 92%respectively,while the protection efficiency was up to 99%under condition of 6%water adsorption of the composite film and ASTM 5B level of adhesion to stainless steel.The composite epoxy emulsion(MGO/EP)was prepared with the functional graphene oxide(MGO)and EP,and MGO was obtained through GO modified with a silane coupling agent(KH550).Then,MGO,the composite MGO/EP emulsion and the emulsion film were characterized comprehensively.The results showed that the protection efficiency of the composite film is up to 99%as well as high hardness and good thermal performance and the comprehensive performance of MGO/EP film is superior to that of GO/EP film.