▎ 摘　　要

NOVELTY - Preparing modified graphene involves mixing graphene oxide, 1,3,5-triazine and dimethylformamide, transferring to a PTFE-lined reactor, introducing nitrogen for protection, heating at 80-150 degrees C, stirring, reacting for 2-10 hours, adding distilled water, filtering, vacuum filtering, drying to obtain a nitrogen-doped graphene oxide, mixing with dimethyl chlorophosphate and an organic solvent, stirring and reacting at 10-80 degrees C for 1-6 hours, filtering, washing several times with methanol, vacuum drying at 60 degrees C for 12 hours, adding the obtained organic phosphorus grafted nitrogen-doped graphene oxide, nickel(II) nitrate hexahydrate and lanthanum(III) nitrate hexahydrate to methanol, ultrasonically dispersing at room temperature for 3 hours, adding 2-methylimidazole, stirring, reacting at room temperature for 12-24 hours, suction filtering, and washing several times with deionized water to remove excess reagents and obtain lanthanum-nickel loaded phosphorus-nitrogen modified graphene. USE - The method is useful for preparing modified graphene, which is useful for preparing modified thermoplastic elastomer (claimed). ADVANTAGE - The method improves the intumescent flame-retardant efficiency of phosphorus-nitrogen modified graphene, helps to improve the mechanical property, electrical conductivity and flame retardance of the matrix material, solves the dispersibility problem of graphene during processing, and gives nano-enhancing effect. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for use of the modified graphene for preparing a modified thermoplastic elastomer by melt blending of lanthanum-nickel loaded phosphorus-nitrogen modified graphene and acrylonitrile butadiene styrene, which involves: (A1) uniformly mixing ethylene-propylene-diene monomer rubber (EPDM), polypropylene (PP) and lanthanum-nickel loaded phosphorus-nitrogen modified graphene in a high-speed mixer, discharging, and granulating by a miniature twin-cone screw extruder at 190-200 degrees C to prepare an intermediate; and (A2) evenly mixing the intermediate, dicumyl peroxide, zinc stearate, triallyl isocyanurate, and antioxidant 1010 (pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate)), dynamically vulcanizing at 180-200 degrees C to prepare a modified EPDM/PP thermoplastic elastomer composite material, using an injection molding machine to inject a sample at 200 degrees C and then using a standard cutting knife to make a sample strip for testing.