Research Of Graphene/Epoxy/Polyacrylate Composite Latex And Coating

Emulsion polymerization is an effective preparation method of waterborne coating which is environmental friendly,and it responds to the call of national sustainable development.Therefore,to enhance aqueous coating performance,various modification method are in research now.In this paper,we prepared epoxy resin(EP)/polyacrylate(PA)composite latex by miniemulsion polymerization,and introduced graphene oxide or graphene nanocomposites;then we obtained composite latex and coating by studying on the graphene oxide preparation method and the composite method;moreover the mechanical performances and anticorrosion properties of various coating have been investigated systematically.The obtained waterborne composite coatings have excellent anticorrosion properties and mechanical performances.The main content is summarised as follows:1.We changed the raw materials and the reaction conditions on the basis of improved Hummers method,and obtained two kinds of graphene oxide.The products were tested by infrared(FTIR),X ray diffraction(XRD),Raman;The results show that two kinds of graphene oxide graphite has been oxidized successfully,but one of them has the higher oxidation degree than another,namely graphene oxide(GO)and higher oxidation degree graphene oxide(HODGO).Both GO and HODGO can disperse in water to stably.2.We obtained a stable PA latex by optimizing the emulsifier system on the basis of miniemulsion polymerization method.Then we prepared GO-PA composite latex and film by direct mixing method,and researched the mechanical properties,water absorption,thermal stability of the composite film though the universal testing machine,weighing method and TGA.We discovered that tensile strength,Young's modulus and thermal decomposition temperature of the composite film increased with the addition of GO(less than 0.8wt%),and water absorption rate decreased under the same condition.3.Introduce EP to the PA latex system.We use HODGO as pickering emulsifier,and prepare HODGO/EP/PA composite latex and film by the method of miniemulsion polymerization.Then we studied the effect of the amount of HODGO and E44 on the mechanical properties and water absorption rate of the film.The results show that E44 and HODGO can improve the tensile strength and Young's modulus,the tensile strength of film containing 20wt%E44 and 0.2wt%HODGO is 13.28MPa,which is about three times as high as the film witout E44 and HODGO.Moreover,E44 and HODGO can decrease the water absorption rate of the film,the water absorption rate of film containing 20wt%E44 and 0.2wt%HODGO reduce to half of film witout E44 and HODGO.4.Introduce HNTs to the GO dispersion.We prepared HNTs-rGO by reduction coagulation method which is conducted under the condition of hydrazine hydrate as reducing agent.The products were tested by FTIR,UV-vis,TEM,zeta potential.The results show that GO has been reduced partly,HNTs and rGO compound effectively though hydrogen bonding,what is more,HNTs-rGO can disperse stably in water over a week,5.HNTs-rGO and EP/PA latex blend directly.The composite latex was mixed with film-forming agent and curing agent,and then prepare films by spraying,the physical and mechanical properties results show that hardness are all 4H and adhesion are all 0 grade;there is no obvious change when the amount of HNTs-rGO is below lwt%;but we discover that the HNTs-rGO/EP/PA composite coating is denser than the EP/PA coating.We evaluate the anti-corrosion property by soak test and salt spray test,the results show that the acid-proof,alkali resistance,salt resistance and water resistance improve when the coatings contain HNTs-rGO;EIS results show that the anticorrosion property of the HNTs-rGO/EP/PA composite coating improve and are effected by the amount of HNTs-rGO;the anticorrosion property of 0.5wt%HNTs-rGO/EP/PA composite coating is the best,time for alkali resistance,salt resistance,water resistance,salt spray resistence is longer than 90 days.