▎ 摘　　要

NOVELTY - A modified graphene epoxy composite anticorrosive coating is prepared by preparing graphene oxide by adopting improved Hummers method, then adding a modifier to the graphene oxide for functional modification, adding hydrazine hydrate during reaction to prepare a modified graphene, and mixing the modified graphene with aqueous epoxy resin. The mass ratio of graphene oxide to hydrazine hydrate is 2:1. The mass ratio of modifier to graphene oxide is (9-11):1. The modifier is hexamethylene diisocyanate or polyisocyanate. USE - Modified graphene epoxy composite anticorrosive coating. ADVANTAGE - The modified graphene epoxy composite anticorrosive coating: adopts functionally modified graphene, which has enhanced dispersibility and solubility in solvent, which solves the problem of easy agglomeration of graphene; improves uniform dispersion of graphene in the aqueous epoxy resin; enhances the interaction and compatibility between the graphene and the epoxy resin segment; and improves corrosion resistance of composite coating by introducing the modified graphene into the aqueous epoxy resin. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the modified graphene epoxy composite anticorrosive coating, which involves: (1) preparing graphene oxide by placing a three-necked flask containing concentrated sulfuric acid in an ice water bath for 5 minutes, adding graphite powder, continuously reacting for 30 minutes, adding sodium nitrate, reacting for 30 minutes, adding potassium permanganate for deep oxidation, finally adding hydrogen peroxide for deepest oxidation to obtain a bright yellow solution, pouring into newly prepared hydrochloric acid solution, discarding supernatant, centrifuging lower product, washing, and drying; (2) preparing a functionally modified graphene by adding the graphene to a water-removed dimethylformamide beaker, transferring to an ultrasonic cleaner, oscillating for 40 minutes, when the graphene oxide is completely dissolved in dimethylformamide, transferring to the three-necked flask, adjusting the pH to 10, adding the modifier, then transferring the three-necked flask to a constant temperature water bath, setting the reaction temperature, reacting for 3 hours, adding hydrazine hydrate, continuously reacting, centrifuging the solution, removing the supernatant, washing the precipitate 3 times with dichloromethane, and drying in a constant temperature drying oven; and (3) adding the functionally modified graphene to N-methylpyrrolidone, dissolving, manually stirring with a glass rod for 5 minutes, then deeply dispersing and dissolving by using an ultrasonic instrument for 30 minutes, adding to the beaker containing aqueous epoxy resin, and stirring with a high-speed stirrer at 2500 rpm. The mass ratio of graphite powder, sodium nitrate and potassium permanganate is 2:1:6.