Study On Polyaniline Grafted Graphene Oxide And Its Application In The Conductive Anticorrosion Coating

Graphene has many excellent properties,such as high melting point, regular structure, high conductivity and good crystallinity etc, but it can not be produced in large and the price is expensive, so it can not meet the broad application of coatings.In situ conjugated graft polymer on surface of graphene, on the one hand is conducive to the formation of conductive network, improve the conductive properties of the filler,on the other hand, it can improve graphene dispersion and reduce the amount of graphene used, make it wide used on coating. Polyaniline have a lot of advatages,such as good electrical conductivity, high chemical stability, unique corrosion resistance and so on. In this topic, polyaniline was grafted on the surface of graphene in situ, compared with the direct coating or silane coupling agent as a bridge, the polyaniline grafted graphene was more easy formation of conductive channels. The detailed process and conclusions of the experiment are as follows:Preparation of graphene oxide(GO) by improved Hummers method, benzene two amine reaction with epoxy group of the GO, formation of benzene two amine grafted graphene oxide(GO-g), the molecule of Benzene two amine like bridge between GO and polyaniline, preparation of polyaniline grafted modified graphene oxide(GO-g-PANI). Research the product structure and properties ware influenced on graphite oxidation time and m(graphite) :m(aniline). FTIR, TG, XRD, SEM, TEM and Four probe conductor / semiconductor resistivity measuring instrument tests show that: GO was successfully prepared by the improved Hummers method; Polyaniline is grafted on the GO surface by covalent bond instead of physical coating, and the GO-g-PANI is successfully prepared; When oxidation time of graphite is 1 h and m(graphite): m(aniline) is 1:3, the conductive properties of GO-g-PANI is best, the resistivity value is 1.77 ??cm, this can be used as conductive filler for conductive anticorrosion coatings.Preparation of graphene oxide(GO) by Hummers method, GO and ammonia reaction in a high pressure reaction kettle by hydrothermal method, preparation of amino functionalized graphene oxide(GO-N), then GO-N reaction with polyaniline,preparation of polyaniline grafted ammonia amine functionalized graphene oxide(GO-N-PANI). Research the product structure and properties ware influenced onamino functionalized temperature of graphene oxide and m(graphite) :m(aniline).FTIR, TG, XRD, SEM, TEM and Four probe conductor / semiconductor resistivity measuring instrument tests show that: GO was successfully prepared by the Hummers method; Polyaniline is grafted on the surface of GO-N successfully; When amino functionalized temperature of graphene oxide is 85 ? and m(graphite): m(aniline) is 1:3, the conductive properties of GO-N-PANI is best, the resistivity value is 3.35 ??cm.Three conductive coatings were prepared by using three kinds of conductive filler natural graphite, GO-g-PANI and GO-N-PANI, each mixture with epoxy resin E-20, polyamide 650 curing agent and other additives. Change the contents of three kinds of conductive fillers, it influence of the mechanical properties, chemical properties and conductivity of the conductive coating is studied. The mechanical properties of the three kinds of conductive coatings show that, the comprehensive mechanical properties of GO-g-PANI and GO-N-PANI two kinds of conductive coatings are better than that of natural graphite, and when the content of GO-g-PANI and GO-N-PANI ware all less than 50%, this two kinds of conductive coatings have best comprehensive mechanical properties, among all conductive coatings with 4H of pencil hardness, 0 level of adhesion, all less than 2.5 mm of flexibility and 50 Kg?cm of anti impact property. Three kinds conductive coatings of chemical resistance properties show that, GO-g-PANI and GO-N-PANI conductive coatings of acid, alkali and salt resistance ware better than natural graphite conductive coatings, and when the content of GO-g-PANI and GO-N-PANI ware all less than 40%, the surface of the two kinds of conductive coating was not changed after soaking 20 d in three solution of acid, alkali and salt, but the natural graphite coating has been corrosion phenomenon,it shows that the corrosion resistance of GO-g-PANI and GO-N-PANI two kinds of conductive coating is good. The conductive properties of the three kinds of coatings shows that, GO-g-PANI and GO-N-PANI conductive coatings of conductive properties ware better than natural graphite conductive coatings. When the content of GO-g-PANI is 30~40%, resistivity value of GO-g-PANI conductive coatings ware102.59~34.9 ??cm and the comprehensive performance of the coating is the best;When the content of GO-N-PANI is 30 ~ 40%, resistivity value of GO-g-PANI conductive coatings ware 128.83~76.53 ??cm and the comprehensive performance of the coating is the best. GO-g-PANI and GO-N-PANI are two kinds of high performance conductive anticorrosive coatings.