▎ 摘　　要

NOVELTY - Preparing compound flame retardant modified rigid polyvinyl chloride sheet, comprises (i) placing metal magnesium hydroxide, metal aluminum hydroxide water and magnesium carbonate into high-energy planetary ball mill; (ii) preparing graphene oxide, dispersing flake graphite in water, adding potassium permanganate magnetically to stir, continuously adding concentrated sulfuric acid, cooling, transferring mixture to water bath, vigorously stirring, heating, cooling, adding water and 27.5% hydrogen peroxide until the color of the solution turns light yellow, filtering with suction, washing solid with water, and crushing sample into nanoscale graphene oxide by probe ultrasonic method; (iii) mixing layered double metal hydroxide, graphene oxide and vinyl silane coupling agent, heating, reacting, centrifuging, washing, drying, and preparing compound flame retardant; and (iv) mixing polyvinyl chloride resin and compound flame retardant to high-speed mixer, and extruding to obtain product. USE - The method is useful for preparing compound flame retardant modified rigid polyvinyl chloride sheet. ADVANTAGE - The method enables to prepare compound modified flame retardant hard polyvinyl chloride plate which has good synergistic effect, simplifies the process, reduces the production cost, improves flame retardant property of modified polyvinyl chloride hard, and keeps the original excellent performance of the material. The material is more stable to certain degree, exhibits better smoke inhibiting performance, and has certain flame retardance performance. DETAILED DESCRIPTION - Preparing compound flame retardant modified rigid polyvinyl chloride sheet, comprises (i) placing metal magnesium hydroxide, metal aluminum hydroxide water and magnesium carbonate into high-energy planetary ball mill, and controlling the speed of the ball mill, ratio of balls to materials, pH value of the solution, reaction rate and layered inorganic flame retardant product to adjust to obtain layered double metal hydroxides; (ii) using improved Hummer method to prepare graphene oxide, dispersing flake graphite in water, adding potassium permanganate magnetically to stir for 30 minutes, continuously adding concentrated sulfuric acid, cooling by ice bath, stirring for 30 minutes, transferring mixture to 40℃ water bath, vigorously stirring at constant temperature for 2 hours, heating to 100℃, stirring for 15 minutes, cooling to room temperature, adding water and 27.5% hydrogen peroxide until the color of the solution turns light yellow, filtering with suction, washing solid with water, and crushing sample into nanoscale graphene oxide by probe ultrasonic method; (iii) mixing layered double metal hydroxide, graphene oxide and vinyl silane coupling agent, stirring and heating to 40℃, reacting for 2 hours, centrifuging, washing 2-3 times, drying at 100℃ for 24 hours, and preparing compound flame retardant; and (iv) adding polyvinyl chloride resin and compound flame retardant to high-speed mixer, mixing for 1 hour, placing into barrel of extruder, and extruding on the extruder at 180-195℃ to obtain final product. An INDEPENDENT CLAIM is included for compound flame retardant modified rigid polyvinyl chloride sheet, prepared as mentioned above.