▎ 摘　　要

NOVELTY - Polytetrahydrofuran ether diol and graphene-magnetite composite organic magnetic liquid are mixed, heated, cooled, toluene diisocyanate is added, stirred and heated, to obtain graphene-magnetite polyurethane prepolymer. Methylenebis(o-chloroaniline) (chain extender) is added to prepolymer, stirred at room temperature for 1 minute, vacuum-degassed, obtained mixture is added into iron mold preheated to 100-120 degrees C, then cured and dried, to obtain graphene-magnetite polyurethane elastomer composite. USE - Preparation of high-performance graphene-magnetite polyurethane elastomer composite (claimed). ADVANTAGE - The method enables preparation of high-performance magnetic polyurethane elastomer composite having excellent mechanical and magnetic properties. The dispersion and distribution of functional particles in polymer matrix can be improved. DETAILED DESCRIPTION - 2 g Natural flake graphite and 2 g sodium nitrate are added to 46 ml concentrated sulfuric acid under ice-cooling and stirred for 30 minutes at a rate of 600 rpm. 6 g Potassium permanganate is added and stirred for 60 minutes at a rate of 600 rpm. Reaction mixture is stirred for 4 hours at a rate of 400 rpm in 45 degrees C water bath, 80 ml deionized water is added, reacted at 95 degrees C in oil bath, 200 ml deionized water is added when the reaction solution temperature is 95 degrees C, then 16 ml hydrogen peroxide having concentration of 30% is added, obtained residue is washed with 2 mol/L hydrochloric acid solution, deionized water and ethanol several times until the pH of wash liquid is neutral, filtered and dried at 60 degrees C, to obtain graphite oxide. 3.58 g Iron(II) chloride tetrahydrate and 6.08 g iron(III) chloride hexahydrate are dissolved in 90 mL deionized water, stirred at a rate of 500 rpm in 50 degrees C water bath, 90 mL sodium hydroxide solution having concentration of 1.34 mol/L is dripped, reacted for 90 minutes and cooled to room temperature. Reaction solution is subjected to magnetic separation to obtain magnetite magnetic particles, supernatant is removed, ultrasonic dispersion is performed with deionized water, magnetic separation is then carried out, washed 6-8 times until pH of the supernatant is neutral, stirred for 10 minutes, 120 mL deionized water is added and ultrasonically dispersed for 20 minutes, to obtain 0.025 g/mL aqueous magnetite magnetic liquid. Predetermined amount of graphite oxide is added to 120 ml deionized water, ultrasonically dispersed for 1-3 hours, obtained graphene oxide dispersion is reacted in 80 degrees C water bath, 0.025 g/ml aqueous magnetite magnetic liquid is added under nitrogen protection, stirred, ascorbic acid, hydrazine hydrate or hydroiodic acid as reducing agent is added and reacted for 1 hour, to obtain graphene-magnetite composite magnetic liquid. Magnetic separation is carried out, supernatant is removed, ultrasonically dispersed, magnetic separation is carried out and washed 5 times, to obtain graphene-magnetite composite magnetic particles. 0.4 g Graphene-magnetite composite magnetic particles are added to 40 ml mixture of water and polytetramethylene ether glycol, stirred at a rate of 100 rpm, ultrasonically dispersed for 20 minutes, magnetic separation is carried out, supernatant is removed, organic solvent is added, ultrasonically dispersed, magnetic separation is carried out, washed and purified, to obtain graphene-magnetite composite organic magnetic liquid having concentration of 0.005-0.08 g/mL. Polytetrahydrofuran ether diol and graphene-magnetite composite organic magnetic liquid are mixed, and heated at 60-90 degrees C for 30 minutes and 100-120 degrees C for 3-5 hours. Reaction mixture is cooled to 25-40 degrees C, toluene diisocyanate is added, stirred at 40-60 degrees C for 50 minutes and heated at 80-95 degrees C for 1.5-3 hours, to obtain graphene-magnetite polyurethane prepolymer. Methylenebis(o-chloroaniline) (chain extender) is added to prepolymer, stirred at room temperature for 1 minute, vacuum-degassed, obtained mixture is added into iron mold preheated to 100-120 degrees C, then cured for 25-35 minutes and dried at 100 degrees C for 24 hours in oven, to obtain graphene-magnetite polyurethane elastomer composite. The content of graphene-magnetite composite magnetic particles contained in the graphene-magnetite polyurethane elastomer composite is 0-20 wt.% (excluding 0). The mass ratio of graphite oxide and magnetite is 0.05-1.5:1. The mass ratio of polytetrahydrofuran ether glycol, toluene diisocyanate and methylenebis(o-chloroaniline) is 40-220:12-68:7-39.