▎ 摘　　要

NOVELTY - Complex board with electromagnetic shielding performance comprises 45 pts. wt. modified polypropylene fiber, 10 pts. wt. carbon fiber, 30 pts. wt. terylene and 15 pts. wt. modified hollow microsphere, where, the preparation method of the complex board comprises (i) mixing the benzoyl peroxide and styrene in the three mouth flask, and adding starch in the three-mouth flask, heating the material in the three-mouth flask, filtering to obtain the pre-processed hollow microsphere blank, and washing, (ii) foaming pre-processing hollow microsphere, filtering, mixing the filter cake and drying, (iii) mixing the modified graphene oxide and polypropylene, subjecting to pre-needling reinforcing treatment and main needling reinforcing treatment in turn to obtain a pre-treated mixed fiber felt, and (iv) pre-processing the mixed fiber felt in the hot press for hot pressing treatment to obtain the complex board with electromagnetic shielding performance. USE - Complex board for use in facility of automobile. Can also be used in electronic products and electrical appliances. ADVANTAGE - The complex board has excellent electromagnetic shielding performance and noise reduction performance, and low density and good strength. DETAILED DESCRIPTION - Complex board with electromagnetic shielding performance comprises 45 pts. wt. modified polypropylene fiber, 10 pts. wt. carbon fiber, 30 pts. wt. terylene and 15 pts. wt. modified hollow microsphere, where the preparation method of the complex board with electromagnetic shielding performance comprises (i) mixing the benzoyl peroxide and styrene in a mass ratio of 1:20 in the three mouth flask, and adding starch of 0.125 times the mass of the styrene in the three-mouth flask and maleic anhydride with 0.0125 times the mass of styrene was introducing nitrogen into the three-mouth flask at a rate of 30 ml/minute, after removing the air, heating the material in the three-mouth flask at 120℃, stirring and pre-polymerizing for 1.5 hours to obtain the pre-polystyrene mixture, mixing the pre-polystyrene mixture with styrene in a mass ratio of 1:2.5, and adding benzoyl peroxide with 0.02 times of the mass of the pre-polystyrene mixture, stirring and mixing for 40 minutes at the temperature of 65℃ and the rotating speed of 350 revolution/minute to obtain the pre polystyrene dispersion liquid, mixing the pre-polystyrene dispersion liquid with hydroxyethyl cellulose solution with mass fraction of 1 % in the beaker in a volume ratio of 1:5, after polymerizing, cooling the material in the beaker to 40℃, filtering to obtain the pre-processed hollow microsphere blank, washing the pre-processed hollow microsphere blank for 4 times by water to obtain pre-processed hollow microsphere, (ii) foaming pre-processing hollow microsphere at 160℃ for 40 minutes to obtain the hollow microsphere, mixing the hollow microsphere and water in a mass ratio of 1:12 into the flask, and adding potassium periodate 0.1 times the mass of hollow microsphere blank into the flask, stirring and reacting at 80℃ for 2 hours, rotating speed is 500 revolution/minutes, filtering to obtain the filter cake, mixing the filter cake and the mass fraction is 2 % sodium hydroxide solution in a mass ratio of 1:15, and adding 4 times of acrylic acid in the filter cake and the mixture of the sodium hydroxide solution, stirring and mixing at 50℃ for 3 hours, at a rotating speed of 400 revolution/minute, filtering to obtain the filter residue, and drying the filter residue at 85℃ for 2 hours to obtain the modified hollow microsphere, (iii) mixing the modified graphene oxide and polypropylene in a mass ratio of 7:100, stirring and mixing under at 170℃ to obtain the spinning solution, extruding the spinning solution through spinneret hole, cooling and forming to obtain the modified polypropylene fiber with diameter of 0.8 mm and length of 80 mm, taking 45 pts. wt. modified polypropylene fiber, 10 pts. wt. carbon fiber, 30 pts. wt. terylene and 15 pts. wt. modified hollow microsphere, mixing the modified polypropylene fiber with carbon fiber, and adding the modified hollow microsphere polyester, stirring and mixing to obtain the mixed material, carding the mixed material, net forming to obtain the mixed fiber felt, subjecting to pre-needling reinforcing treatment and main needling reinforcing treatment in turn to obtain a pre-treated mixed fiber felt with gram weight of 550 g/m2, and (iv) pre-processing the mixed fiber felt in the hot press for hot pressing treatment to obtain the complex board with electromagnetic shielding performance.