▎ 摘　　要

NOVELTY - Preparing red mud reinforced micro-foamed polyvinyl chloride composite material comprises e.g. (i) taking 45 wt.% polyvinyl chloride, 26-40 wt.% active red mud, 6-20 wt.% chlorinated polyethylene (CPE), 5 wt.% composite foaming agent, 2 wt.% heat stabilizer, 1 wt.% lubricant and 1 wt.% antioxidant, the composite foaming agent is silicon dioxide/graphene double-shell hollow microspheres supported OBSH composite foaming agent, the composite foaming agent has a gas generation volume of 100-150ml/g, has good thermal stability at 100-180 degrees C, and has a decomposition percentage less than 2%; and (ii) depositing a graphene oxide layer on the surface of polystyrene microspheres to prepare graphene oxide/polystyrene core-shell structure microspheres by surface electrostatic adsorption and using the hydrothermal reduction reaction method to reduce the graphene oxide to generate graphene/polystyrene core-shell structure microspheres. USE - The method is useful for preparing red mud reinforced micro-foamed polyvinyl chloride composite material. ADVANTAGE - The method: produces OBSH composite blowing agent supported by SiO2/graphene double-shell hollow microspheres and polyvinyl chloride power sheath with uniform and dense pores and high mechanical properties and quality. DETAILED DESCRIPTION - Preparing red mud reinforced micro-foamed polyvinyl chloride composite material comprises (i) taking 45 wt.% polyvinyl chloride, 26-40 wt.% active red mud, 6-20 wt.% chlorinated polyethylene (CPE), 5 wt.% composite foaming agent, 2 wt.% heat stabilizer, 1 wt.% lubricant and 1 wt.% antioxidant, the composite foaming agent is silicon dioxide/graphene double-shell hollow microspheres supported OBSH composite foaming agent, the composite foaming agent has a gas generation volume of 100-150ml/g, has good thermal stability at 100-180 degrees C, and has a decomposition percentage less than 2%; (ii) depositing a graphene oxide layer on the surface of polystyrene microspheres to prepare graphene oxide/polystyrene core-shell structure microspheres by surface electrostatic adsorption and using the hydrothermal reduction reaction method to reduce the graphene oxide to generate graphene/polystyrene core-shell structure microspheres; (iii) preparing the graphene/polystyrene core-shell structure microspheres obtained in step (ii) into 20% an ethanol dispersion, taking 10-20 ml dispersion, adding 0.2-1 g sodium dodecylbenzene sulfonate surfactant, 3-6 ml concentrated ammonia and 60-100 ml ethanol aqueous solution, carrying out ultrasonic treatment for 60-100 minutes, adding 2-10 ml ethyl orthosilicate drop wise, stirring magnetically for 48 hours at room temperature, alternate washing with ethanol and water, filtering, drying, calcination and carrying out dissolution corrosion method to obtain silicon dioxide/graphene double-shell hollow microspheres; (iii) taking 1 g silicon dioxide/graphene double-shell hollow microsphere prepared in step (iii), soaking it in the foaming agent 0.2-0.6 mol/liter 4,4'-oxo-(benzenesulfonylhydrazine) (OBSH) solution medium, magnetic stirring for 20-40 minutes, carrying out ultrasonic treatment for 10-20 minutes, allowing to stand for 12-24 hours, filtering with suction, washing alternately with ethanol and deionized water, and drying at 60 degrees C to obtain silicon dioxide/graphene double-shell hollow microspheres supporting OBSH composite blowing agent, where in the step (ii), the hydrothermal reduction reaction method comprises using hydrazine hydrate hydrothermal reduction treatment of graphite oxide, the concentration range of which is 10-40 mg/ml, the hydrothermal reaction temperature is 200-240 degrees C and the reaction time is 1-3 hours and in the step (iii), the dissolution corrosion reaction method comprises dispersing the obtained silicon dioxide/graphene/polystyrene core-shell structure microspheres in tetrahydrofuran solvent, stirring continuously, where the mass ratio of silicon dioxide/graphene/polystyrene microspheres to tetrahydrofuran solvent is 100-150:1, and the reaction time 24-48 hours, where the particle size of the active red mud is 2000-3000 meshes, and the preparation method comprises adding the refined red mud powder into a high-speed mixer, heating to 80-100 degrees C, stirring at 80-100 revolutions/minute for 1-2 hours, adding 1% by mass of the long-chain alkyl trimethoxysilane coupling agent of the red mud powder, stirring at a high speed for 0.5-1 hour at 400-500 revolutions/minute, cooling to room temperature, the heat stabilizer is composed of calcium stearate and barium stearate in a mass ratio of 1-3:1, the lubricant is composed of polyethylene wax and paraffin wax in a mass ratio of 1:1, the antioxidant is composed of AT-1010 and AT-168 in a mass ratio of 1:1 and preparing the above materials by high-speed mixing, plasticization and granulation to obtain a red mud reinforced micro-foamed PVC composite material or the preparation of red mud reinforced micro-foamed polyvinyl chloride composite material comprises (a) adding polyvinyl chloride, active red mud and toughening agent into the high-speed mixer, mixing at high speed for 10-30 minutes at a material temperature of 80-100 degrees C, adding compound foaming agent, heat stabilizer, lubricant and antioxidant, mixing at high speed for 20-30 minutes and discharging for use; (b) melting, extruding and pelletizing the blended material obtained in step (a) by a twin-screw extruder, where the process parameters for controlling the twin-screw extruder are as follows the temperature in the first zone is 100-120 degrees C, the temperature in the second zone is 110-130 degrees C, the temperature in the third zone is 130-150 degrees C, and the temperature in the fourth zone is 150-170 degrees C, five zone temperature is 160-180 degrees C, die temperature is 140-160 degrees C, feeding speed is 100-200 revolutions/minute at screw speed of 200-400 revolutions/minute and extruding and granulating. An INDEPENDENT CLAIM is also included for preparing red mud-reinforced micro-foamed polyvinyl chloride electric power sheath, comprising preparing red mud reinforced micro-foamed polyvinyl chloride composite material as specified further comprises extruding the red mud-reinforced micro-foamed polyvinyl chloride composite material through a pipe extruder, and the process parameters of the pipe extruder are controlled as follows the temperature of the barrel 1 zone is 100-120 degrees C, the temperature of the barrel 2 zone is 110-130 degrees C, the temperature of the barrel 3 zone is 130-150 degrees C, the temperature of the barrel 4 zone is 150-170 degrees C, and the temperature of the barrel 5 zone is 160-180 degrees C, the temperature of die head 1 zone is 160-180 degrees C, die 2 zone temperature is 170-190 degrees C, die 3 zone temperature is 150-170 degrees C, extrusion molding speed is 0.5 m/min.