▎ 摘　　要

NOVELTY - Preparing modified graphene oxide/hydrotalcite composite material comprises (i) dissolving sulfanilic acid in sodium hydroxide aqueous solution, adding sodium nitrate and mixing, adding concentrated hydrochloric acid to diazotization reaction, and generating diazonium salt solution, (ii) adding graphene oxide into the water, stirring and ultrasonically dispersing, adding diazonium salt solution to react, preparing the modified graphene oxide dispersion, (iii) placing steel slag powder in the ball mill, adding anhydrous ethanol ball milling, drying, adding to the phosphoric acid aqueous solution, acutely stirring, centrifuging and taking supernatant, using sodium hydroxide, allowing to stand and crystallizing, filtering, washing, and drying, (iv) adding hydrotalcite into water, vigorously stirring to make hydrotalcite fully swelling and scattering to prepare white slurry, adding to modified graphene oxide dispersion, stirring and reacting, filtering and washing, and drying. USE - The preparation method of modified graphene oxide/hydrotalcite composite material is useful in polypropylene composite material (claimed). ADVANTAGE - The method improves the strength and flame retardance of polypropylene material, has better mechanical property, and has good dispersing effect in the polypropylene system. DETAILED DESCRIPTION - Preparing modified graphene oxide/hydrotalcite composite material comprises (i) dissolving sulfanilic acid in sodium hydroxide aqueous solution, adding sodium nitrate and uniformly mixing, adding concentrated hydrochloric acid to diazotization reaction, and generating diazonium salt solution, (ii) adding graphene oxide into the water, fully stirring and ultrasonically dispersing, adding diazonium salt solution to react, preparing the modified graphene dispersion, (iii) placing the steel slag powder in the ball mill, adding anhydrous ethanol ball milling, drying, adding to the phosphoric acid aqueous solution, acutely stirring, centrifuging and taking the supernatant, using sodium hydroxide to adjust the pH of the supernatant to 12-13, allowing to stand and crystallizing, filtering, washing, and drying to obtain hydrotalcite, (iv) adding hydrotalcite into the water, vigorously stirring to make the hydrotalcite fully swelling and scattering to prepare white slurry to obtain hydrotalcite emulsion, adding to the modified oxide dispersion graphene, stirring and reacting, filtering and washing, and drying. INDEPENDENT CLAIMS are also included for A modified graphene oxide/hydrotalcite composite material prepared by above method; A flame-retardant reinforced polypropylene composite material comprises 95-100 pts. wt., preferably 95-96 pts. wt. polypropylene, 5-15 pts. wt., preferably 5-10 pts. wt. ethylene-octene copolymer, 5-20 pts. wt., preferably 5-15 pts. wt. modified graphene composite material, 2-5 pts. wt., preferably 3-5 pts. wt. naphthenic oil, 0.5-2 pts. wt., preferably 1-2 pts. wt. stearic acid, 1-5 pts. wt. preferably 1.5-2 pts. wt. zinc stearate, 2-10 pts. wt., preferably 3-5 pts. wt. zinc oxide, and 1-5 pts. wt., preferably 2-3 pts. wt. antioxidant; and A preparation method of flame-retardant reinforced polypropylene composite material comprising (i) placing polypropylene granules into the torque rheometer for mixing, sequentially adding ethyleneoctylene copolymer, stearic acid, zinc stearate, zinc oxide, antioxidant, naphthenic oil, modified graphene oxide/hydrotalcite composite material, mixing for 20-30 minutes, and (ii) placing mixed material for 24-32 hours, tableting mechanism to form 3-5 mm sheet, using double-screw extruder for extruding and granulating after cutting to obtain flame-retardant reinforced polypropylene composite material.