▎ 摘　　要

NOVELTY - Preparing diisocyanate modified graphene anti-wear energy-saving lubricating oil comprises e.g. (i) (a) adding natural flake graphite into large beaker containing concentrated sulfuric acid, adding mixture of sodium nitrate and potassium permanganate, adding hydrogen peroxide, (b) adding into dimethylacetamide, (ii) carrying out infiltration reaction of the product obtained in step (i) in alcohol solution of organic amine, (iii) mixing product obtained in step (ii) with SN 5w-40 lubricating oil, then adding into stainless steel reaction vessel, (iv) connecting reaction vessel containing product of step (iii) by circulation motor and ultra-high speed colloid mill, and (v) placing diisocyanate-modified graphene lubricating oil in precipitation tank for isolation and precipitation, recycling large particle solid phase materials for next batch of ultra-high speed grinding dispersion, vacuum dehydrating ultrasonically dispersed graphene lubricating oil and defoaming and filtering. USE - The method is useful for preparing diisocyanate modified graphene anti-wear energy-saving lubricating oil. ADVANTAGE - The modified graphene: has complete structure, low layer number, uniform dispersion and stability. DETAILED DESCRIPTION - Preparing diisocyanate modified graphene anti-wear energy-saving lubricating oil comprises (i) (a) adding 10 g 200 mesh natural flake graphite slowly under stirring into 2000 ml large beaker containing 230 ml concentrated sulfuric acid, and maintaining the temperature change at 0 plus minus 1 degrees C, adding mixture of 5 g sodium nitrate and 30 g potassium permanganate, reacting in constant temperature water bath at 35 plus minus 3 degrees C for 2 hours, stirring for 30 minutes, adding 460 ml water, adjusting temperature of water bath to 98 degrees C for 15 minutes, diluting with 1400 ml warm water, adding 5 wt.% 5-10 ml hydrogen peroxide, allowing to stand for 20-24 hours, filtering, washing the filter cake with 5% hydrochloric acid for 5-6 times until the sulfate in filtrate is not detected with barium chloride solution, centrifugating the obtained material with deionized water until supernatant is neutralized and drying in vacuum drying oven at 35-40 degrees C to obtain graphite oxide, (b) adding into 250 ml dimethylacetamide, sonicating at power of 200-250 W for 1.5-2 hours, then transferring into water bath at 80-85 degrees C, adding 8 g diisocyanate, stirring at constant temperature for 4-6 hours, reducing temperature to 60-65 degrees C, adding 5 g benzoquinone, continue magnetic stirring reaction at constant temperature for 4-6 hours, lowering temperature to room temperature, filtering, washing with dichloromethane for 2-3 times, drying in vacuum drying oven at 35-40 degrees C to obtain diisocyanate modified graphene, (ii) carrying out infiltration reaction of the product obtained in step (i) in alcohol solution of organic amine for 10 hours, subjecting suspension to centrifugal filtration, and drying under vacuum to obtain modified graphene having diisocyanate linked to long molecular chain of lipophilic organic amine, (iii) mixing product obtained in step (ii) with SN 5w-40 lubricating oil, then adding into stainless steel reaction vessel equipped with stirrer and high-speed saw-tooth disperser, heating reactor jacket to 50-80 degrees C by heat-conducting oil, starting main stirrer of reaction kettle, stirrer rotates at 48 revolutions/minute for 30-60 minutes, adding 0.5-5 wt.% co-dispersant into reaction kettle of lubricating oil, stirring at constant speed for 30-60 minutes, adding 0.5-2.5 wt.% lubricating oil into suspension stabilizer in reaction kettle, stirring at constant speed for 10-30 minutes, starting high-speed disperser and adjusting speed of disperser to 2800 revolutions/minute, pre-dispersing modified graphene in lubricating oil and stirring continuously for 8 hours, (iv) connecting reaction vessel containing product of step (iii) by circulation motor and ultra-high speed colloid mill, increasing speed of starting motor ultra-high speed colloid mill to 14000 revolutions/minute through motor frequency converter, super-high speed grinding and dispersing diisocyanate-modified graphene lubricating oil for 3-5 hours, and (v) placing diisocyanate-modified graphene lubricating oil in precipitation tank for isolation and precipitation, recycling large particle solid phase materials for next batch of ultra-high speed grinding dispersion, passing isolation liquid through series of two-pole ultrasonic generator to control ultrasonic frequency to 20 Hz, power is 500-1400 W, flow rate is 2-8 l/minute, ultrasonic temperature is 0-12 degrees C, vacuum dehydrating ultrasonically dispersed graphene lubricating oil and defoaming in vacuum machine at 120-180 degrees C and filtering to room temperature to obtain final product.