A high-performance PA, ABS 5G electromagnetic shielding composite material and its preparation method

Abstract

The present application relates to the technical field of functionalized PA / ABS composite materials. More specifically, it relates to a high-performance PA / ABS 5G electromagnetic shielding composite material and its preparation method. A high-performance PA / ABS 5G electromagnetic shielding composite material is obtained by melt extrusion of a PA / ABS alloy material and an electromagnetic shielding additive; the electromagnetic shielding additive contains molybdenum disulfide, the electromagnetic shielding additive is modified with dopamine, and the surface of the PA / ABS alloy material is modified with epoxy functionalization. The high-performance PA / ABS 5G electromagnetic shielding composite material of the present application has both excellent electromagnetic shielding effect and impact strength, and can meet the electromagnetic shielding requirements in a variety of environments.

Description

Technical Field

[0001] The present application relates to the technical field of functionalized PA / ABS composite materials, and more specifically, to a high-performance PA, ABS 5G electromagnetic shielding composite material and a preparation method thereof. Background Art

[0002] With technological advancements and the rapid development of the 5G era, the widespread use of intelligent wireless communication devices has led to an increasingly prominent problem of electromagnetic interference (EMI). For example, EMI generated by lightning, solar flares, and electrostatic discharge can adversely affect power transmission lines and electronic systems. This increasingly serious problem of electromagnetic pollution can easily interfere with the normal operation of electronic equipment and even pose a threat to human health. Therefore, the development of efficient absorbing materials is a key research topic in aerospace, 5G communications, military, and civilian fields.

[0003] Transition metal sulfides have become a hot topic in recent years as electromagnetic shielding materials due to their exceptional chemical stability, unique layered structure, and large specific surface area. For example, MoS2 has a unique defect structure, large specific surface area, and numerous active sites, which facilitates the realization of multiple reflections and polarization effects.

[0004] However, with the addition of MoS2, the impact strength of the PA / ABS material as the matrix will deteriorate significantly. Therefore, there is an urgent need for a PA / ABS 5G electromagnetic shielding composite material that has both excellent impact resistance and electromagnetic shielding effect to adapt to the market. Summary of the Invention

[0005] In order to improve the defects of conventional MoS2-PA / ABS composite materials in terms of insufficient impact strength and electromagnetic shielding effect, the present application provides a high-performance PA, ABS 5G electromagnetic shielding composite material and a preparation method thereof.

[0006] In the first aspect, the present application provides a high-performance PA, ABS 5G electromagnetic shielding composite material, which adopts the following technical solution:

[0007] A high-performance PA and ABS 5G electromagnetic shielding composite material, which is obtained by melt extrusion of PA / ABS alloy material and electromagnetic shielding additives;

[0008] The electromagnetic shielding additive contains molybdenum disulfide, the electromagnetic shielding additive is modified by dopamine, and the surface of the PA / ABS alloy material is modified by epoxy functionalization.

[0009] Molybdenum disulfide has a large specific surface area and is easily agglomerated in PA / ABS alloy materials. In addition, the interfacial bonding strength between molybdenum disulfide and PA / ABS alloy materials is insufficient. Therefore, with the addition of MoS2, the impact strength of PA / ABS material as the matrix will be significantly deteriorated.

[0010] When the electromagnetic shielding additive is modified with dopamine and the surface of the PA / ABS alloy material is modified with epoxy functionalization, dopamine can undergo oxidative self-polymerization on the surface of the electromagnetic shielding additive to synthesize polydopamine. Polydopamine contains active functional groups such as hydroxyl, amino, and indole. The above functional groups can react with the epoxy groups on the surface of the PA / ABS alloy material to form a cross-linked network, thereby effectively improving the interfacial bonding strength between the electromagnetic shielding additive and the PA / ABS alloy material, and effectively improving the impact strength of the PA / ABS material.

[0011] Preferably, the electromagnetic shielding additive is a Mo-based metal sulfide / graphene composite material.

[0012] Graphene is a form of carbon. In the field of electromagnetic shielding, due to its two-dimensional structure, large dielectric loss, rich surface area, high carrier mobility, multi-defect structure and low density, when graphene is used in combination with molybdenum disulfide, its electromagnetic shielding effect can be further enhanced.

[0013] Preferably, the electromagnetic shielding additive is a MoCo bimetallic sulfide / graphene composite material.

[0014] Preferably, the method for preparing the electromagnetic shielding material comprises the following steps:

[0015] A1. Soaking graphene in a hydrochloric acid solution, then heating at 20-30°C for 8-12 hours, then washing with deionized water until neutral, and drying at 70-90°C for 20-30 hours to obtain acidified graphene;

[0016] dissolving 2-methylimidazole in deionized water to obtain a 2-methylimidazole solution, dissolving cobalt nitrate in deionized water to obtain a cobalt nitrate solution, and mixing the 2-methylimidazole solution and the cobalt nitrate solution to obtain a mixed solution;

[0017] The acidified graphene was immersed in the mixed solution for 3-5 hours, then washed with deionized water until neutral, and dried at 70-90°C for 20-30 hours to obtain a Co metal organic framework / acidified graphene;

[0018] A2. Treating the Co metal organic framework / acidified graphene with O2-Ar radio frequency plasma for 15-25 min at an output power of 200-400 W to obtain a Co metal organic framework / acidified graphene containing oxygen vacancies;

[0019] A3. Deionized water, sodium molybdate, and thioacetamide are mixed, and then the oxygen vacancy-containing Co metal organic framework / acidified graphene is immersed therein. The mixture is sealed and reacted at 140-160°C for 4-8 hours. After cooling to room temperature, the mixture is filtered, washed, and dried, and finally the surface is modified with dopamine to obtain a MoCo bimetallic sulfide / graphene composite material.

[0020] The electromagnetic shielding material uses O2-Ar radio frequency plasma technology to treat acidified graphene and form a Co metal organic framework rich in oxygen vacancies on the surface, which increases surface defects, is conducive to the reflection and scattering of electromagnetic waves, thereby broadening the electromagnetic wave absorption performance and compensating for the impedance mismatch and insufficient dielectric loss caused by a single component. At the same time, the introduction of bimetallic sulfide further enhances dipole polarization, giving it excellent electromagnetic wave loss performance.

[0021] Preferably, the method for preparing the electromagnetic shielding material comprises the following steps:

[0022] A1. Soak 0.1-0.2 g of graphene in 80-120 ml of 7.8 wt% hydrochloric acid solution, then heat at 20-30° C. for 8-12 h, then wash with deionized water until neutral, and dry at 70-90° C. for 20-30 h to obtain acidified graphene;

[0023] Dissolve 0.1-0.2 g of 2-methylimidazole in 80-120 ml of deionized water to obtain a 2-methylimidazole solution, dissolve 0.04-0.06 g of cobalt nitrate in 40-60 ml of deionized water to obtain a cobalt nitrate solution, and mix the 2-methylimidazole solution and the cobalt nitrate solution to obtain a mixed solution;

[0024] 0.1 g of acidified graphene was immersed in the mixed solution for 3-5 h, then washed with deionized water until neutral, and dried at 70-90 ° C for 20-30 h to obtain Co metal organic framework / acidified graphene;

[0025] A2. Treating the Co metal organic framework / acidified graphene with O2-Ar radio frequency plasma for 15-25 min at an output power of 200-400 W to obtain a Co metal organic framework / acidified graphene containing oxygen vacancies;

[0026] A3. Mix 80-120 ml of deionized water, 0.1-0.2 g of sodium molybdate, and 0.1-0.2 g of thioacetamide, then immerse the oxygen-vacancy-containing Co metal-organic framework / acidified graphene therein, seal and react at 140-160° C. for 4-8 hours, cool to room temperature, filter, wash, and dry to obtain a crude MoCo bimetallic sulfide / graphene composite material;

[0027] A4. The crude MoCo bimetallic sulfide / graphene composite material is subjected to dopamine surface modification to finally obtain a MoCo bimetallic sulfide / graphene composite material.

[0028] Preferably, in A4, the specific steps of dopamine surface modification are: adding 0.4-0.6 g of crude MoCo bimetallic sulfide / graphene composite material to 200-400 ml of deionized water, ultrasonically dispersing in an ice bath for 20-40 min, then adding 1-2 g of dopamine hydrochloride and adjusting the pH to 8.5 with Tris-HCl buffer, and finally stirring the reaction at 50-70 ° C for 20-30 h, and then centrifuging and washing the lower precipitate, and drying at 70-90 ° C for 20-30 h to obtain a MoCo bimetallic sulfide / graphene composite material.

[0029] Preferably, the preparation method of the PA / ABS alloy material comprises the following steps:

[0030] B1. Mix glucose, sodium pyrophosphate, and deionized water. After the solids are completely dissolved, add ferrous sulfate aqueous solution and mix well to obtain a base solution.

[0031] B2. Polybutadiene latex, deionized water and isopropylbenzene hydroperoxide are sequentially added to the base solution, and the reaction is continued under nitrogen. Styrene monomer, acrylonitrile monomer, glycidyl methacrylate, isopropylbenzene hydroperoxide and tert-dodecyl mercaptan are then added and the reaction is continued. After the reaction is completed, demulsification, washing, dehydration and drying are performed to obtain a PA / ABS alloy material.

[0032] Preferably, the preparation method of the PA / ABS alloy material comprises the following steps:

[0033] B1. Mix 0.4-0.6 g of glucose, 0.4-0.6 g of sodium pyrophosphate, and 500-1000 ml of deionized water. After the solids are completely dissolved, add 8-12 ml of a 1 mg / L aqueous solution of ferrous sulfate and mix well to obtain a base solution.

[0034] B2. 180-220 g of polybutadiene latex, 300-500 ml of deionized water, and 0.04-0.06 ml of cumene hydroperoxide are sequentially added to the base solution, and the reaction is continued at 60-70° C. under nitrogen. Then, 50-70 g of styrene monomer, 15-25 g of acrylonitrile monomer, 1-3 g of glycidyl methacrylate, 0.5-1.0 ml of cumene hydroperoxide, and 0.2-0.4 ml of tert-dodecyl mercaptan are added, and the reaction is continued. After the reaction is completed, demulsification, washing, dehydration, and drying are performed to obtain a modified ABS alloy material;

[0035] B3, mixing the modified ABS material with PA6 resin at a mass ratio of (20-30): (70-80), and then extruding to obtain a PA / ABS alloy material;

[0036] The temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are: 220-230℃, 230-240℃, and 230-240℃ respectively.

[0037] In a second aspect, the present application provides a method for preparing a high-performance PA and ABS 5G electromagnetic shielding composite material, which adopts the following technical solution:

[0038] A method for preparing a high-performance PA and ABS 5G electromagnetic shielding composite material, comprising the following steps:

[0039] The PA / ABS alloy material and the electromagnetic shielding additive are mixed in a mass ratio of (5-10):1, and then extruded to obtain the PA / ABS alloy material;

[0040] The temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are: 220-230℃, 230-240℃, and 230-240℃ respectively.

[0041] In summary, this application has the following beneficial effects:

[0042] 1. When the electromagnetic shielding additive is modified with dopamine and the surface of the PA / ABS alloy material is modified with epoxy functionalization, dopamine can undergo oxidative self-polymerization on the surface of the electromagnetic shielding additive to synthesize polydopamine. Polydopamine contains active functional groups such as hydroxyl, amino, and indole. The above functional groups can react with the epoxy groups on the surface of the PA / ABS alloy material to form a cross-linked network, thereby effectively improving the interfacial bonding strength between the electromagnetic shielding additive and the PA / ABS alloy material, and effectively improving the impact strength of the PA / ABS material.

[0043] 2. Graphene is a form of carbon. In the field of electromagnetic shielding, due to its two-dimensional structure, large dielectric loss, rich surface area, high carrier mobility, multi-defect structure and low density, when graphene is used in combination with molybdenum disulfide, its electromagnetic shielding effect can be further enhanced.

[0044] 3. The electromagnetic shielding material uses O2-Ar radio frequency plasma technology to treat acidified graphene and form a Co metal organic framework rich in oxygen vacancies on the surface, which increases surface defects, is conducive to the reflection and scattering of electromagnetic waves, thereby broadening the electromagnetic wave absorption performance and compensating for the impedance mismatch and insufficient dielectric loss caused by a single component. At the same time, the introduction of bimetallic sulfide further enhances dipole polarization, giving it excellent electromagnetic wave loss performance. DETAILED DESCRIPTION

[0045] The present application is further described in detail below in conjunction with Examples 1 to 5 and Comparative Example 1.

[0046] Graphene CAS: 1034343-98-0; Hydrochloric acid CAS: 7647-01-0; 2-Methylimidazole CAS: 693-98-1; Cobalt nitrate CAS: 10141-05-6; Sodium molybdate CAS: 10102-40-6; Thioacetamide CAS: 62-55-5; Dopamine hydrochloride CAS: 62-31-7; Tris-HCl buffer CAS: 1185-53-1; Glucose CAS: 50-99-7 Sodium pyrophosphate CAS: 7722-88-5; Ferrous sulfate CAS: 7720-78-7; Polybutadiene latex Henan Wokas Biological CAS: 9003-17-2; Styrene monomer CAS: 100-42-5; Acrylonitrile monomer CAS: 107-13-1; Cumene hydroperoxide CAS: 80-15-9; Glycidyl methacrylate CAS: 106-91-2; Tert-dodecyl mercaptan CAS: 25103-58-6.

[0047] A high-performance PA and ABS 5G electromagnetic shielding composite material, which is obtained by mixing a PA / ABS alloy material and an electromagnetic shielding additive in a mass ratio of 9:1 and then extruding and melt-extruding;

[0048] Among them, the temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are: 220℃, 230℃, and 240℃ respectively.

[0049] The electromagnetic shielding additive is molybdenum disulfide, the electromagnetic shielding additive is modified by dopamine, and the surface of the PA / ABS alloy material is modified by epoxy functionalization.

[0050] The specific steps of dopamine surface modification are:

[0051] Add 0.5 g of molybdenum disulfide to 300 ml of deionized water, ultrasonically disperse for 30 min in an ice bath, then add 1.5 g of dopamine hydrochloride and adjust the pH value to 8.5 with Tris-HCl buffer. Finally, stir and react at 60 ° C for 25 h, then centrifuge and wash to remove the lower layer of precipitate, and dry at 80 ° C for 25 h to obtain an electromagnetic shielding additive.

[0052] The preparation method of PA / ABS alloy material comprises the following steps:

[0053] B1. Mix 0.5 g of glucose, 0.5 g of sodium pyrophosphate, and 800 ml of deionized water. After the solids are completely dissolved, add 10 ml of a 1 mg / L aqueous solution of ferrous sulfate and mix well to obtain a base solution.

[0054] B2. 200 g of polybutadiene latex, 400 ml of deionized water, and 0.05 ml of cumene hydroperoxide were sequentially added to the base solution, and the reaction was continued at 65° C. under nitrogen. Then, 60 g of styrene monomer, 20 g of acrylonitrile monomer, 2 g of glycidyl methacrylate, 0.8 ml of cumene hydroperoxide, and 0.3 ml of tert-dodecyl mercaptan were added, and the reaction was continued. After the reaction was completed, the emulsion was broken, washed, dehydrated, and dried to obtain a modified ABS alloy material.

[0055] B3, mixing the modified ABS material and PA6 resin at a mass ratio of 25:75, and then extruding to obtain a PA / ABS alloy material;

[0056] The temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are 220°C, 230°C, and 240°C respectively.

[0057] The difference from Example 1 is that the electromagnetic shielding additive is a molybdenum disulfide / graphene composite material;

[0058] The preparation method of the electromagnetic shielding additive comprises the following steps:

[0059] A1. Soak 0.1 g of graphene in 100 ml of 7.8 wt% hydrochloric acid solution, then heat at 25°C for 10 h, then wash with deionized water until neutral, and dry at 80°C for 25 h to obtain acidified graphene;

[0060] A2. 100 ml of deionized water, 0.15 g of sodium molybdate, and 0.15 g of thioacetamide were mixed, and then the acidified graphene was immersed therein. The mixture was sealed and reacted at 150° C. for 6 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a molybdenum disulfide / graphene composite material.

[0061] A4. Modify the molybdenum disulfide / graphene composite material with dopamine. The specific steps of the dopamine surface modification are as follows:

[0062] 0.5 g of molybdenum disulfide / graphene composite material was added to 300 ml of deionized water, ultrasonically dispersed in an ice bath for 30 min, and then 1.5 g of dopamine hydrochloride was added and the pH value was adjusted to 8.5 with Tris-HCl buffer. Finally, the reaction was stirred at 60 ° C for 24 h, and then the lower layer of precipitate was removed by centrifugal washing and dried at 80 ° C for 24 h to obtain an electromagnetic shielding additive.

[0063] The difference from Example 1 is that the electromagnetic shielding additive is a MoCo bimetallic sulfide / graphene composite material;

[0064] The preparation method of the electromagnetic shielding additive comprises the following steps:

[0065] A1. Soak 0.1 g of graphene in 100 ml of 7.8 wt% hydrochloric acid solution, then heat at 25°C for 10 h, then wash with deionized water until neutral, and dry at 80°C for 25 h to obtain acidified graphene;

[0066] Dissolve 0.1 g of 2-methylimidazole in 100 ml of deionized water to obtain a 2-methylimidazole solution, dissolve 0.05 g of cobalt nitrate in 50 ml of deionized water to obtain a cobalt nitrate solution, and mix the 2-methylimidazole solution and the cobalt nitrate solution to obtain a mixed solution;

[0067] 0.1 g of acidified graphene was immersed in the mixed solution for 4 h, then washed with deionized water until neutral, and dried at 80 °C for 24 h to obtain Co metal organic framework / acidified graphene;

[0068] A2. Treating the Co metal organic framework / acidified graphene with O2-Ar radio frequency plasma for 20 min at an output power of 300 W to obtain a Co metal organic framework / acidified graphene containing oxygen vacancies;

[0069] A3. 100 ml of deionized water, 0.15 g of sodium molybdate, and 0.15 g of thioacetamide were mixed, and then the oxygen vacancy-containing Co metal organic framework / acidified graphene was immersed therein. The mixture was sealed and reacted at 150° C. for 6 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a crude MoCo bimetallic sulfide / graphene composite material.

[0070] A4. The crude MoCo bimetallic sulfide / graphene composite material is subjected to dopamine surface modification. The specific steps of the dopamine surface modification are as follows:

[0071] 0.5 g of crude MoCo bimetallic sulfide / graphene composite material was added to 300 ml of deionized water and ultrasonically dispersed in an ice bath for 30 min. Then, 1.5 g of dopamine hydrochloride was added and the pH value was adjusted to 8.5 with Tris-HCl buffer. Finally, the mixture was stirred at 60 ° C for 24 h, and then the lower precipitate was removed by centrifugation and washed with water, and dried at 80 ° C for 24 h to obtain an electromagnetic shielding additive.

[0072] Example 4-Example 5

[0073] The difference from Example 3 is that the added amounts of graphene, cobalt nitrate and sodium molybdate are different, as shown in Table 1.

[0074] Table 1 Addition amount of graphene, cobalt nitrate and sodium molybdate in Examples 3 to 5

[0075]

[0076] Comparative Example 1

[0077] The difference from Example 1 is that the electromagnetic shielding additive is no longer modified with dopamine, that is, molybdenum disulfide is directly added, and the surface of the PA / ABS alloy material is no longer epoxy functionalized, that is, glycidyl methacrylate is no longer added.

[0078] 1. Electromagnetic shielding effect test

[0079] The test used a vector network analyzer, fortunately Agilent N5244A, the test method was coaxial transmission reflection method, the test model was NRW two-port network model, the test frequency was 2-18 GHz, and three samples were taken from Examples 1 to 5 and Comparative Example 1 respectively. The samples were annular in structure with an inner diameter of 3 mm, an outer diameter of 7 mm, and a thickness of 5 mm. The maximum reflection loss was tested.

[0080] 2. Impact strength test

[0081] Three samples were taken from each of Examples 1 to 5 and Comparative Example 1, and then the impact strength of the samples was tested in accordance with ISO 180:2019 “Determination of Izod Impact Strength of Plastics” and the average value was taken.

[0082] The test data are shown in Table 2.

[0083] Table 2 Test data table of Examples 1 to 5 and Comparative Example 1

[0084]

[0085] With reference to Examples 1 to 5 and Comparative Example 1, it can be seen that the impact strengths of Examples 1 to 5 are significantly increased compared to Comparative Example 1. This indicates that dopamine modification of electromagnetic shielding additives and epoxy modification of PA / ABS alloy materials can effectively improve the mechanical properties of composite materials.

[0086] The reason is that when the electromagnetic shielding additive is modified with dopamine and the surface of the PA / ABS alloy material is modified with epoxy functionalization, dopamine can undergo oxidative self-polymerization on the surface of the electromagnetic shielding additive to synthesize polydopamine, and polydopamine contains active functional groups such as hydroxyl, amino, and indole. The above functional groups can react with the epoxy groups on the surface of the PA / ABS alloy material to form a cross-linked network, thereby effectively improving the interfacial bonding strength between the electromagnetic shielding additive and the PA / ABS alloy material, and effectively improving the impact strength of the PA / ABS material.

[0087] Compared to Comparative Example 1, Example 1 shows a slight improvement in maximum reflection loss, demonstrating that dopamine-modified electromagnetic shielding additives and epoxy-modified PA / ABS alloys can also slightly enhance the composite's electromagnetic shielding effectiveness. This may be due to the fact that epoxy and dopamine modifications effectively improve the compatibility of the electromagnetic shielding additive with the PA / ABS alloy, indirectly enhancing the composite's electromagnetic shielding effectiveness.

[0088] With reference to Example 1 and Example 2 and in combination with Table 2, it can be seen that, relative to Example 1, the maximum reflection loss of Example 2 is further increased, which indicates that the addition of graphene can further enhance the electromagnetic shielding effect of the composite material.

[0089] The reason is that graphene is a form of carbon. In the field of electromagnetic shielding, due to its two-dimensional structure, large dielectric loss, rich surface area, high carrier mobility, multi-defect structure and low density, when graphene is used in combination with molybdenum disulfide, its electromagnetic shielding effect can be further enhanced.

[0090] Referring to Example 2-Example 3 and combining with Table 2, it can be seen that compared with Example 2, the maximum reflection loss of Example 3 is significantly increased, which shows that replacing molybdenum disulfide with bimetallic sulfide can significantly improve the electromagnetic shielding effect of the composite material.

[0091] The reason is that the electromagnetic shielding material uses O2-Ar radio frequency plasma technology to treat acidified graphene and form a Co metal organic framework rich in oxygen vacancies on the surface, which increases surface defects and is conducive to the reflection and scattering of electromagnetic waves, thereby broadening the electromagnetic wave absorption performance and compensating for the impedance mismatch and insufficient dielectric loss caused by a single component. At the same time, the introduction of bimetallic sulfide further enhances dipole polarization, giving it excellent electromagnetic wave loss performance.

[0092] With reference to Examples 3-5 and in combination with Table 2, it can be seen that the maximum reflection losses of Examples 4-5 are slightly lower than those of Example 3. This indicates that when graphene, cobalt nitrate and sodium molybdate are added in the amounts of Example 3, the prepared composite material will have a better electromagnetic shielding effect.

[0093] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high-performance PA, ABS 5G electromagnetic shielding composite material, characterized in that: It is made by melt extrusion of PA / ABS alloy material and electromagnetic shielding additives; The electromagnetic shielding additive is a MoCo bimetallic sulfide / graphene composite material; The preparation method of the electromagnetic shielding additive comprises the following steps: A1. Soaking graphene in a hydrochloric acid solution, then heating at 20-30°C for 8-12 hours, then washing with deionized water until neutral, and drying at 70-90°C for 20-30 hours to obtain acidified graphene; dissolving 2-methylimidazole in deionized water to obtain a 2-methylimidazole solution, dissolving cobalt nitrate in deionized water to obtain a cobalt nitrate solution, and mixing the 2-methylimidazole solution and the cobalt nitrate solution to obtain a mixed solution; The acidified graphene was immersed in the mixed solution for 3-5 hours, then washed with deionized water until neutral, and dried at 70-90°C for 20-30 hours to obtain a Co metal organic framework / acidified graphene; A2. Treating the Co metal organic framework / acidified graphene with O2-Ar radio frequency plasma for 15-25 min at an output power of 200-400 W to obtain a Co metal organic framework / acidified graphene containing oxygen vacancies; A3. Deionized water, sodium molybdate, and thioacetamide were mixed, and then the oxygen vacancy-containing Co metal organic framework / acidified graphene was immersed therein. The mixture was sealed and reacted at 140-160° C. for 4-8 hours. After cooling to room temperature, the mixture was filtered, washed, and dried. Finally, the surface was modified with dopamine to obtain a MoCo bimetallic sulfide / graphene composite material. The preparation method of the PA / ABS alloy material comprises the following steps: B1. Mix 0.4-0.6 g of glucose, 0.4-0.6 g of sodium pyrophosphate, and 500-1000 ml of deionized water. After the solids are completely dissolved, add 8-12 ml of a 1 mg / L aqueous solution of ferrous sulfate and mix well to obtain a base solution. B2. 180-220 g of polybutadiene latex, 300-500 ml of deionized water, and 0.04-0.06 ml of cumene hydroperoxide are sequentially added to the base solution, and the reaction is continued at 60-70° C. under nitrogen. Then, 50-70 g of styrene monomer, 15-25 g of acrylonitrile monomer, 1-3 g of glycidyl methacrylate, 0.5-1.0 ml of cumene hydroperoxide, and 0.2-0.4 ml of tert-dodecyl mercaptan are added, and the reaction is continued. After the reaction is completed, demulsification, washing, dehydration, and drying are performed to obtain a modified ABS alloy material; B3, mixing the modified ABS material with PA6 resin at a mass ratio of (20-30): (70-80), and then extruding to obtain a PA / ABS alloy material; The temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are 220-230°C, 230-240°C, and 230-240°C respectively.

2. The high-performance PA, ABS 5G electromagnetic shielding composite material according to claim 1, characterized in that: The preparation method of the electromagnetic shielding additive comprises the following steps: A1. Soak 0.1-0.2 g of graphene in 80-120 ml of 7.8 wt% hydrochloric acid solution, then heat at 20-30° C. for 8-12 h, then wash with deionized water until neutral, and dry at 70-90° C. for 20-30 h to obtain acidified graphene; Dissolve 0.1-0.2 g of 2-methylimidazole in 80-120 ml of deionized water to obtain a 2-methylimidazole solution, dissolve 0.04-0.06 g of cobalt nitrate in 40-60 ml of deionized water to obtain a cobalt nitrate solution, and mix the 2-methylimidazole solution and the cobalt nitrate solution to obtain a mixed solution; 0.1 g of acidified graphene was immersed in the mixed solution for 3-5 h, then washed with deionized water until neutral, and dried at 70-90 ° C for 20-30 h to obtain Co metal organic framework / acidified graphene; A2. Treating the Co metal organic framework / acidified graphene with O2-Ar radio frequency plasma for 15-25 min at an output power of 200-400 W to obtain a Co metal organic framework / acidified graphene containing oxygen vacancies; A3. Mix 80-120 ml of deionized water, 0.1-0.2 g of sodium molybdate, and 0.1-0.2 g of thioacetamide, then immerse the oxygen-vacancy-containing Co metal-organic framework / acidified graphene therein, seal and react at 140-160° C. for 4-8 hours, cool to room temperature, filter, wash, and dry to obtain a crude MoCo bimetallic sulfide / graphene composite material; A4. The crude MoCo bimetallic sulfide / graphene composite material is subjected to dopamine surface modification to finally obtain a MoCo bimetallic sulfide / graphene composite material.

3. The high-performance PA, ABS 5G electromagnetic shielding composite material according to claim 2, characterized in that: In A4, the specific steps of dopamine surface modification are: 0.4-0.6 g of crude MoCo bimetallic sulfide / graphene composite material was added to 200-400 ml of deionized water, ultrasonically dispersed in an ice bath for 20-40 min, and then 1-2 g of dopamine hydrochloride was added and the pH value was adjusted to 8.5 with Tris-HCl buffer. Finally, the mixture was stirred and reacted at 50-70° C. for 20-30 h, and then the lower precipitate was removed by centrifugation and washed with water, and dried at 70-90° C. for 20-30 h to obtain a MoCo bimetallic sulfide / graphene composite material.

4. A method for preparing the high-performance PA, ABS 5G electromagnetic shielding composite material according to any one of claims 1 to 3, characterized in that: The steps are: The PA / ABS alloy material and the electromagnetic shielding additive are mixed in a mass ratio of (5-10):1, and then extruded to obtain a composite material; The temperatures of the three zones of the twin-screw extruder from the feeding section to the nozzle are 220-230°C, 230-240°C, and 230-240°C respectively.

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