▎ 摘　　要

NOVELTY - A high-strength electromagnetic shielding and thermally conductive polybutylene terephthalate (PBT)/polyethylene terephthalate (PET) nanocomposite material comprises 70-80 pts. wt. PBT, 20-30 pts. wt. PET, 5-10 pts. wt. toughening agent, 5-10 pts. wt. graphene-iron(II,III) oxide composite filler, 0.05-1 pt. wt. filler surface treatment agent and 0.5-1.4 pt. wt. antioxidant. The graphene-iron(II,III) oxide composite filler is prepared by adding large-diameter graphene micro-sheet, small-diameter graphene micro-sheet and sodium dodecylbenzene sulfonate to deionized water, ultrasonically dispersing, obtaining a graphene dispersion, adding ferric chloride hexahydrate and ferrous chloride tetrahydrate to deionized water, obtaining a ferrous salt/iron salt solution, adding the ferrous salt/iron salt solution to the graphene dispersion, ultrasonically dispersing, adding aqueous ammonia, adjusting pH to 8-10, reacting, suction-filtering, washing the filter cake, and drying. USE - High-strength electromagnetic shielding and thermally conductive polybutylene terephthalate/polyethylene terephthalate nanocomposite material. ADVANTAGE - The nanocomposite material has excellent electromagnetic shielding effect through the synergistic effect of dielectric loss and magnetic loss. Graphene with different sheet diameters improves mechanical property of the nanocomposite material while forming electrical and thermal network. DETAILED DESCRIPTION - A high-strength electromagnetic shielding and thermally conductive polybutylene terephthalate (PBT)/polyethylene terephthalate (PET) nanocomposite material comprises 70-80 pts. wt. PBT, 20-30 pts. wt. PET, 5-10 pts. wt. toughening agent, 5-10 pts. wt. graphene-iron(II,III) oxide composite filler, 0.05-1 pt. wt. filler surface treatment agent and 0.5-1.4 pt. wt. antioxidant. The graphene-iron(II,III) oxide composite filler is prepared by adding large-diameter graphene micro-sheet, small-diameter graphene micro-sheet and sodium dodecylbenzene sulfonate to deionized water, ultrasonically dispersing for 3-5 hours, obtaining a graphene dispersion, adding ferric chloride hexahydrate and ferrous chloride tetrahydrate to deionized water, obtaining a ferrous salt/iron salt solution, adding the ferrous salt/iron salt solution to the graphene dispersion, ultrasonically dispersing for 1-2 hours, adding aqueous ammonia, adjusting pH to 8-10 under stirring at 700 rpm and nitrogen protection atmosphere, heating resultant solution to 40-60 degrees C, reacting for 1-2 hours, cooling the reaction solution to room temperature, suction-filtering, washing the filter cake with ethanol and deionized water until neutral, and drying at 70-90 degrees C for 6 hours. The mass ratio of large-diameter graphene micro-sheet, small-diameter graphene micro-sheet, sodium dodecylbenzene sulfonate and deionized water is 2-3:1:1.5-4:300-400. The mass ratio of ferric chloride hexahydrate, ferrous chloride tetrahydrate and deionized water is 1-2:1:40-60. The mass ratio of ferrous salt/iron salt solution and graphene dispersion is 1.7-2.6:1. An INDEPENDENT CLAIM is included for preparation of the nanocomposite material, which involves uniformly mixing the graphene-iron(II,III) oxide composite filler and filler surface treatment agent in a high-speed mixer, adding polybutylene terephthalate, polyethylene terephthalate, toughening agent and antioxidant, mixing, extruding mixed material by a twin-screw extruder, and granulating.