▎ 摘　　要

NOVELTY - Preparing graphene composite coating comprises (i) adding 5-7 pts. wt. sodium nitrate, 1-3 pts. wt. flake graphite and 3-5 pts. wt. potassium permanganate to 100 pts. wt. concentrated sulfuric acid, mixing uniformly, taking an ice bath, heating, reacting, dissolving whole reaction system in water, adding hydrogen peroxide, washing with hydrochloric acid and demineralized water, centrifuging, and drying to obtain graphene oxide, (ii) obtaining graphene oxide polypyrrole compound, (iii) obtaining reduced graphene oxide polypyrrole compound, and (iv) taking aqueous-based epoxy resin emulsion and deionized water, mixing, using ultrasonic to assist dispersion, adding aqueous-based film-forming aids and reduced graphene oxide polypyrrole compound, stirring, mixing aqueous-based epoxy curing agent and deionized water, stirring, mixing obtained first component and second component, stirring, adding emulsifier, dispersant, defoaming agent, and wetting agent, stirring and mixing. USE - The method is useful for preparing graphene composite coating, which is used as a heavy-duty anti-corrosion coating in relatively harsh corrosive environments e.g. ships and bridges. ADVANTAGE - The method provides graphene composite coating with good water penetration resistance, high protection capability, excellent anti-corrosion effect, improved corrosion resistance, strong protection ability, and is simple and economical. DETAILED DESCRIPTION - Preparing graphene composite coating comprises (i) adding 5-7 pts. wt. sodium nitrate, adding 1-3 pts. wt. flake graphite and 3-5 pts. wt. potassium permanganate to 100 pts. wt. concentrated sulfuric acid, mixing uniformly, taking an ice bath for 1-3 hours, heating to 100-110 degrees C, reacting for 1-3 hours, dissolving the whole reaction system in 150-250 pts. wt. water, adding hydrogen peroxide until the solution is golden yellow, washing with hydrochloric acid and demineralized water, centrifuging for many times, adjusting the pH to 5-6 and drying to obtain graphene oxide, (ii) taking 0.4-0.6 pts. wt. graphene oxide composite prepared in step (i), and 0.4-0.6 pts. wt. N-vinylamide polymer, adding into 60-80 pts. wt. hydrochloric acid for ultrasonic assisted dispersion for 1 hour, placing the reaction system on ice bath, dropping pyrrole monomer liquid, stirring for 1 hour, dropping 100 pts. wt. ammonium persulfate hydrochloric acid solution to the obtained mixture emulsion, reacting in ice water for 18-30 hours, and centrifugal washing with acetone and deionized water respectively to obtain graphene oxide polypyrrole compound, (iii) taking 0.5-0.7 pts. wt. graphene oxide-polypyrrole compound, adding 200 parts of deionized water for ultrasonic assisted dispersion for 1 hour, adding 0.3-0.5 parts of reducing agent, stirring for 1 hour, placing the product in an oil bath to keep the temperature at 120-130 degrees C, condensing and refluxing for 2-4 hours, filtering, adding acetone and deionized water for centrifugal washing, drying, and obtaining the reduced graphene oxide polypyrrole compound, and (iv) taking 20 pts. wt. aqueous-based epoxy resin emulsion and 20 pts. wt. deionized water, mixing uniformly, using ultrasonic to assist dispersion, adding 7 pts. wt. aqueous-based film-forming aids and 0.15 pts. wt. reduced graphene oxide polypyrrole compound prepared in step (iii), and stirring for 4 hours under the assistance of ultrasonic to obtain the first component, mixing 18 pts. wt. aqueous-based epoxy curing agent and 12 pts. wt. deionized water uniformly, stirring for 2 hours under the assistance of ultrasonic to obtain the second component, mixing the obtained first component and second component, stirring for 2 hours under the assistance of ultrasound, adding 0.2 pts. wt. emulsifier, 0.2 pts. wt. dispersant, 0.5 pts. wt. defoaming agent, 0.2 pts. wt. wetting agent in sequence, stirring and mixing uniformly.