▎ 摘　　要

NOVELTY - Preparing graphene/epoxy resin composite material comprises (i) oxidizing scaly graphite powder to obtain graphene/ethanol mixed solution, (ii) adding an epoxy resin into graphene/ethanol mixed solution, dissolving graphene using two-phase extraction method to obtain graphene/epoxy resin mixture and vacuum drying, and (iii) ultrasonic processing graphene/epoxy resin mixture, preheating, mixing preheated graphene/epoxy resin mixture and preheated curing agent, stirring to obtain graphene/epoxy resin prepolymer, preheating and reacting. USE - The method is useful for preparing graphene/epoxy resin composite material (claimed). ADVANTAGE - The method is simple, utilizes ethanol as solvent which can be easily volatilized and is environmentally friendly. The composite material has increased tensile strength of 34.9-124.8 %, impact strength of 15.4-105.1% and glass transition temperature of 5-19 degrees C. DETAILED DESCRIPTION - Preparing graphene/epoxy resin composite material comprises (i) adding scaly graphite powder into a container, adding 90-98% concentrated sulfuric acid, placing the container in an ice water bath, stirring under speed of 250-300 revolutions/minute for 30-60 minutes, stirring under speed of 150-200 revolutions/minute, adding potassium permanganate and sodium nitrate, constant stirring and reacting for 2-3 hours, stirring under speed of 150-200 revolutions/minute and reacting at room temperature for 2-4 hours, placing in water bath at 35-40 degrees C and reacting for 24-30 hours, and adding 30-35% hydrogen peroxide to obtain viscous solution, where the mass to volume ratio of flaky graphite powder and 90-98% concentrated sulfuric acid is 1 g:(40-60 ml), the mass ratio of flaky graphite powder and potassium permanganate is 1:(8-9), the mass ratio of flaky graphite powder and sodium nitrate is 1:(1-1.5), and the mass to volume ratio of potassium permanganate and 30-35% hydrogen peroxide is 1 g:(3-5 ml), centrifugal precipitating the viscous solution to obtain precipitate, adding 96-99% ethanol solution to obtain graphene/ethanol mixed solution, washing graphene/ethanol mixed solution using 96-99% ethanol solution for 3-5 times to obtain graphene/ethanol mixed solution, ultrasonic processing under power of 60-70 W for 4-6 hours to obtain graphene/ethanol mixed solution, where the mass to volume ratio of graphene and ethanol in graphene/ethanol mixed solution is 1 g:(5-10 ml), (ii) adding an epoxy resin into graphene/ethanol mixed solution, dissolving graphene using two-phase extraction method to obtain graphene/epoxy resin mixture and vacuum drying the mixture at 40-60 degrees C for 72-144 hours, where the mass to volume ratio of graphene/ethanol mixed solution and epoxy resin is 1 ml:(10-100 g), and (iii) ultrasonic processing graphene/epoxy resin mixture under power of 60-70 W for 30-60 minutes, and preheating graphene/epoxy resin mixture and curing agent in oven at 60-80 degrees C for 2-3 hours to obtain preheated graphene/epoxy resin mixture and preheated curing agent, mixing preheated graphene/epoxy resin mixture and preheated curing agent and stirring under speed of 100-150 revolutions/minute for 4-5 minutes to obtain graphene/epoxy resin prepolymer, preheating in high vacuum silicone grease coated polyfluortetraethylene mold at 50-65 degrees C for 120-180 minutes, curing in an oven at 70-80 degrees C for 2-3 hours, reacting at 125-135 degrees C for 2.5-3.5 hours, and reacting at 150-160 degrees C for 1-2 hours to obtain graphene/epoxy resin composite material.