▎ 摘　　要

NOVELTY - Graphene is prepared by carrying out chemical oxidation of graphite oxide. A silicone rubber base material is prepared by obtaining silicone rubber solution (A) by dissolving methyl vinyl silicone rubber in tetrahydrofuran, obtaining graphene dispersion (B) by dispersing graphene in tetrahydrofuran, mixing solution (A) and dispersion (B), dispersing in tetrahydrofuran, separating tetrahydrofuran and obtaining rubber material. The rubber material is mixed with vulcanizing agent, vulcanized and cured, to obtain graphene/silicone rubber pressure-sensitive conductive composite. USE - Preparation of graphene/silicone rubber pressure-sensitive conductive composite used for pressure sensor and electromagnetic shielding product. ADVANTAGE - The method enables preparation of graphene/silicone rubber pressure-sensitive conductive composite having low percolation threshold, and excellent antistatic property. The graphene/silicone rubber pressure-sensitive conductive composite exhibits significant positive piezoresistive effect. DETAILED DESCRIPTION - Graphene is prepared by carrying out chemical oxidation of graphite oxide by adding natural graphite flakes, potassium persulfate and phosphorus pentoxide to concentrated sulfuric acid, ultrasonically dispersing for 5 minutes, magnetically stirring at 80 degrees C in an oil bath for 6 hours, vacuum-filtering, washing filter cake, drying in vacuum, grinding, adding to a beaker, adding concentrated sulfuric acid, ultrasonically dispersing, adding potassium permanganate, stirring in ice-water bath using electric mixer for 4 hours, adding deionized water to the water bath, maintaining at 40 degrees C, stirring for 2 hours, adding 3-10 times deionized water, adding hydrogen peroxide, obtaining bright yellow suspension of graphite oxide, sedimenting, centrifuging, washing to neutral, drying at 40 degrees C in vacuum, grinding, obtaining graphite oxide powder, subjecting to high-temperature reduction by placing graphite oxide powder in a quartz tube sealed at one end, filling vacuum and argon gas, carrying out high-temperature reduction at 1050 degrees C for 30 seconds and obtaining graphene powder. Then, a silicone rubber base material is prepared using ultrasonically-assisted solution mixing method by dissolving 100 pts. wt. methyl vinyl silicone rubber in tetrahydrofuran, obtaining silicone rubber solution (A), ultrasonically-dispersing 0.5-5 pts. wt. graphene in tetrahydrofuran for 1 hour, obtaining graphene dispersion (B), mixing silicone rubber solution (A) and graphene dispersion (B), ultrasonically dispersing for 30 minutes, replacing thermostatic ultrasonic cleaner with rotary evaporator water bath, ultrasonically dispersing in tetrahydrofuran by rotary evaporation, separating tetrahydrofuran, drying in vacuum and obtaining rubber material. The obtained rubber material is added to 0.5-2 parts mass 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane vulcanizing agent, uniformly mixed in an open mill, mixture is placed in preheated mold, vulcanized at 170 degrees C in vulcanizing machine for 20 minutes and cured at 200 degrees C for 4 hours, to obtain graphene/silicone rubber pressure-sensitive conductive composite.