CN107286649B - Electromagnetic microwave shielding composite material and preparation method thereof - Google Patents
Electromagnetic microwave shielding composite material and preparation method thereof Download PDFInfo
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Abstract
The invention relates to an electromagnetic microwave shielding composite material and a preparation method thereof, belonging to the technical field of polymer-based magnetic composite materials. The invention aims to provide a preparation method of a novel high-performance broadband electromagnetic microwave shielding composite material. The method comprises the steps of firstly realizing in-situ polymerization on the surface of carbon-based iron powder by a solution method to obtain a bisphthalonitrile/carbon-based iron powder prepolymer, and then preparing the bisphthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material by glue preparation, cloth soaking, cloth drying and calendering. The electromagnetic shielding composite material with light weight, high temperature resistance, high mechanical strength, flame resistance, radiation resistance and adjustable performance can be successfully prepared by adopting the method, and the material not only has excellent mechanical property and heat resistance, but also has excellent electromagnetic shielding efficiency.
Description
Technical Field
The invention relates to an electromagnetic microwave shielding composite material and a preparation method thereof, belonging to the technical field of polymer-based magnetic composite materials.
Background
With the rapid development and wide application of modern microelectronic technology and high-frequency wireless communication technology, the number of electronic devices is increased rapidly, and the miniaturization and densification degree of chips in the devices is increased day by day, so that the electromagnetic interference phenomenon and the electromagnetic pollution problem between the electronic devices are increasingly highlighted, thereby not only greatly interfering the generation, transmission and reception of signals of electronic communication equipment, but also bringing potential threats to human beings and ecological systems. Therefore, research on developing novel materials with excellent electromagnetic shielding capability is increasing, and especially wave-absorbing materials with light weight and high-efficiency electromagnetic shielding performance applied to special fields are receiving attention of more and more researchers.
The carbonyl iron powder is used as an advanced wave-absorbing material, has excellent high-frequency magnetism, can reduce the using amount of an absorbent and the thickness of the material, has small particles, large specific surface area and high activity, and can widen the bandwidth of the wave-absorbing material. But because of large density and difficult molding processing, the composite requirements of light weight, high mechanical strength, wide qualified frequency band and strong absorption of the wave-absorbing material can not be simultaneously met. Therefore, the hybrid nano composite material combining the advantages of the organic/high molecular material resisting extreme environment and the traditional inorganic electromagnetic shielding material into a whole is produced, and the organic/inorganic hybrid nano composite not only can reduce the density of the material and improve the processability, but also can obtain the composite rarefied material with wide frequency band, high mechanical strength and strong wave-absorbing performance.
The bisphthalonitrile resin is used as a high-performance thermosetting resin, has the characteristics of excellent heat resistance, chemical stability, flame retardance, good processability and the like, is widely applied in the high-technology fields of aerospace, microelectronics, machinery and the like, and becomes one of the most important branches of the thermosetting resin. The performance of the material can be improved by compounding the bisphthalonitrile resin with carbonyl iron powder, but the brittleness of a network structure formed after the bisphthalonitrile resin is cured limits the application of the bisphthalonitrile resin in the advanced technical field; meanwhile, the mechanical property of the composite material is further reduced by adding a large amount of inorganic filler.
Disclosure of Invention
In order to overcome the defects, the technical problem solved by the invention is to provide a preparation method of a novel high-performance broadband electromagnetic microwave shielding composite material, so that the polymer-based electromagnetic microwave shielding composite material with low density, good mechanical strength, wide shielding frequency band and strong absorption can be prepared in batches, and the application range of the carbon-based iron powder magnetic material as the electromagnetic microwave shielding material is widened.
The preparation method of the electromagnetic microwave shielding composite material comprises the following steps of:
a. uniformly mixing carbonyl iron powder and a bisphthalonitrile solution to obtain a uniform dispersion liquid;
b. stirring the uniform dispersion liquid at 180-220 ℃ for 2-4 h, naturally cooling to room temperature, pouring into deionized water, precipitating, filtering and washing to obtain green powder;
c. mixing the green powder with an organic solvent, stirring for 1-2 hours at 50-70 ℃ to obtain a colloid, and cooling to room temperature; the organic solvent is a mixed solution of 1, 4-dioxane and N, N-dimethylformamide;
d. soaking the aramid fiber 1313 fiber cloth in the colloid, taking out, removing the organic solvent, and performing compression molding to obtain the electromagnetic microwave shielding composite material.
Preferably, in the step a, the solute of the bisphthalonitrile solution is bisphthalonitrile, the solvent is N-methylpyrrolidone, and the concentration is 50-200 mg/mL; the preferred concentration is 50 mg/mL.
Preferably, in the step a, the mass ratio of carbonyl iron powder to bisphthalonitrile is 0.5-1.5: 1; the mass ratio of carbonyl iron powder to bisphthalonitrile is preferably 1.5: 1.
Preferably, in step b, the homogeneous dispersion is stirred at 200 ℃ for 4 h.
In the step c, the volume ratio of 1, 4-dioxane to N, N-dimethylformamide is preferably 0.8-0.95: 0.05-0.2. The mass ratio of the green powder to the organic solvent is preferably 0.8-1.5: 1.
In the step d, the following operation is preferably adopted for removing the organic solvent: airing the soaked prepreg fiber cloth for 20-28 h at room temperature, and then drying the cloth in a drying oven at 150-200 ℃ for 3-5 min to obtain blackened prepreg fiber cloth; more preferably, the soaked prepreg fiber cloth is dried for 24 hours at room temperature and then dried in an oven at 180 ℃ for 5 minutes to obtain the blackened prepreg fiber cloth.
In the step d, the preferred press forming process parameters are as follows: standing at 180-220 ℃ for 3-6 min, adding 4-6 MPa of pressure, releasing the pressure, and repeating for three times; then, adjusting the pressure to 8-12 MPa, repeatedly releasing for three times, then applying the pressure to 14-16 MPa, and pressing according to the following procedures: 180-220 ℃/1h, 230-250 ℃/2h, 270-290 ℃/3h and 310-330 ℃/4h to obtain a black and bright plate;
more preferably, the mixture is placed at 200 ℃ for 5min, then the pressure of 5MPa is added, then the pressure is released, and the steps are repeated for three times; the pressure was then adjusted to 10MPa, released three times repeatedly, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
The invention also provides the electromagnetic microwave shielding composite material prepared by the method.
According to the electromagnetic microwave shielding composite material, the bisphthalonitrile resin and the aramid 1313 fiber cloth are compounded to prepare the continuous fiber reinforced bisphthalonitrile resin based composite material, so that the continuous fiber reinforced bisphthalonitrile resin based composite material has excellent mechanical property and heat resistance, and also has excellent electromagnetic shielding property. The maximum reflection intensity of the composite material to electromagnetic waves is-29.6 dB, and the bandwidth range of more than-10 dB can be widened to 9.2-18 GHz.
Compared with the prior art, the invention has the following beneficial effects:
(1) the bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material can be successfully prepared by the method, and can be processed into different thicknesses, sizes and shapes according to different requirements.
(2) In the composite material, the matrix resin contains a large amount of crosslinkable matrixes, and the heat resistance and the heat stability of the composite material can be further improved through high-temperature crosslinking reaction under the action of metal particles.
(3) According to the method, a series of electromagnetic shielding composite materials with light weight, high temperature resistance, high mechanical strength, flame resistance, radiation resistance and adjustable performance are obtained by changing the content of the carbon-based iron powder, and the electromagnetic shielding composite materials are suitable for the field of electromagnetic shielding materials for extreme environments.
(4) The method is simple and easy to operate, and is easy to realize industrialization.
Drawings
Fig. 1 is a scanning electron microscope image of a phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material prepared in example 1 of the present invention.
Fig. 2 is a scanning electron microscope image of the phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material prepared in example 2 of the present invention.
Fig. 3 is a scanning electron microscope image of the phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material prepared in example 3 of the present invention.
Fig. 4 is an electromagnetic shielding effectiveness graph of the phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material prepared in embodiments 1 to 3 of the present invention.
Detailed Description
The preparation method of the electromagnetic microwave shielding composite material comprises the following steps of:
a. uniformly mixing carbonyl iron powder and a bisphthalonitrile solution to obtain a uniform dispersion liquid;
b. stirring the uniform dispersion liquid at 180-220 ℃ for 2-4 h, naturally cooling to room temperature, pouring into deionized water, precipitating, filtering and washing to obtain green powder;
c. mixing the green powder with an organic solvent, stirring for 1-2 hours at 50-70 ℃ to obtain a dark green colloid, and cooling to room temperature; the organic solvent is a mixed solution of 1, 4-dioxane and N, N-dimethylformamide,
d. soaking the aramid fiber 1313 fiber cloth in the colloid, taking out, removing the organic solvent, and performing compression molding to obtain the electromagnetic microwave shielding composite material.
The invention relates to a preparation method of an electromagnetic microwave shielding composite material, which has the following reaction formula:
r is
The first step of reaction is prepolymerization reaction, the bisphthalonitrile is catalyzed by metal iron particles to obtain a bisphthalonitrile prepolymer (namely an iron phthalocyanine oligomer) containing carbonyl iron powder, the reaction is mainly carried out in the step b, and the second step of reaction is crosslinking reaction and is mainly carried out during the step d of compression molding.
and step a, mainly dispersing carbonyl iron powder in a bisphthalonitrile solution to ensure the smooth proceeding of the subsequent polymerization reaction. Preferably, the bisphthalonitrile solution is prepared by dissolving bisphthalonitrile resin monomer in N-methylpyrrolidone, and the concentration of the bisphthalonitrile solution is 50-200 mg/mL, and more preferably 50 mg/mL. More preferably, the mass ratio of the carbonyl iron powder to the bisphthalonitrile is 0.5-1.5: 1, and still more preferably, the mass ratio of the carbonyl iron powder to the bisphthalonitrile is 1.5: 1. In order to disperse the solution more uniformly, the specific operation of blending is preferably as follows: mechanically stirring for 1-2 h under the ultrasonic condition.
And b, a prepolymerization reaction, wherein the bisphthalonitrile is catalyzed by metal iron particles to obtain a bisphthalonitrile prepolymer (namely an iron phthalocyanine oligomer) containing carbonyl iron powder, and preferably, in the b step, the uniform dispersion liquid is stirred for 4 hours at 200 ℃.
Preferably, the washing in the step b is 3-5 times of washing respectively by deionized water and absolute ethyl alcohol.
In the step c, green powder is mainly dissolved in an organic solvent to prepare a colloidal solution, wherein in the organic solvent, the volume ratio of 1, 4-dioxane to N, N-dimethylformamide is (0.8-0.95): (0.05-0.2); the mass ratio of the green powder to the organic solvent is 0.8-1.5: 1.
and d, compounding the aramid fiber 1313 fiber cloth with the carbonyl iron powder-containing bisphthalonitrile prepolymer to prepare the bisphthalonitrile/carbon-based iron powder/aramid fiber 1313 fiber cloth three-component composite material.
Specifically, the colloid can be placed in a tray, and the cut aramid 1313 fiber cloth (20cm × 20cm) can be immersed in the colloid solution.
The removal of the organic solvent can preferably be carried out by: airing the soaked prepreg fiber cloth at room temperature for 20-28 hours in a layer to volatilize the solvent to obtain green prepreg fiber cloth; and then drying the cloth in a drying oven at 150-200 ℃ for 3-5 min to finally obtain the blackened prepreg fiber cloth. Preferably, the soaked prepreg fiber cloth is dried for 24 hours at room temperature and then dried in an oven at 180 ℃ for 5 minutes to obtain the blackened prepreg fiber cloth.
The ordinary press forming method is applicable to the present invention. The material can be processed into different thicknesses, sizes and shapes according to different requirements during compression molding. In order to improve the mechanical properties, the press forming preferably comprises the following steps: cutting and laying the prepreg fiber cloth, placing the cloth in a grinding tool coated with a release agent, and pressing and molding the cloth on a hydraulic press. The specific pressing process is as follows: and (3) standing at 180-220 ℃ for 3-6 min, adding 4-6 MPa of pressure, releasing the pressure, and repeating the steps for three times. And then adjusting the pressure to 8-12 MPa, repeatedly releasing for three times to remove air and solvent in the prepreg interlayer, then applying the pressure to 14-16 MPa, and pressing according to the following procedures: 180-220 ℃/1h, 230-250 ℃/2h, 270-290 ℃/3h and 310-330 ℃/4h to obtain a black and bright plate, namely the electromagnetic microwave shielding composite material. During this pressing, a cross-linking reaction will occur, enhancing the properties of the material.
A more preferred pressing process is as follows: standing at 200 deg.C for 5min, adding 5MPa pressure, releasing pressure, and repeating for three times; the pressure was then adjusted to 10MPa, released three times repeatedly, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
The invention also provides the electromagnetic microwave shielding composite material prepared by the method.
According to the electromagnetic microwave shielding composite material, the bisphthalonitrile resin and the aramid 1313 fiber cloth are compounded to prepare the continuous fiber reinforced bisphthalonitrile resin based composite material, so that the continuous fiber reinforced bisphthalonitrile resin based composite material has excellent mechanical property and heat resistance, and also has excellent electromagnetic shielding property. The maximum reflection intensity of the composite material to electromagnetic waves is-29.6 dB, and the bandwidth range of more than-10 dB can be widened to 9.2-18 GHz.
The following examples are provided to further illustrate the embodiments of the present invention and are not intended to limit the scope of the present invention. The examples used a phthalonitrile resin monomer of bisphenol a structure.
Example 1
(1) Dissolving 25g of bisphthalonitrile resin monomer in 500mL of N-methyl pyrrolidone to obtain a bisphthalonitrile solution with the concentration of 50 mg/mL;
(2) adding 12.5g of carbonyl iron powder into the bisphthalonitrile solution obtained in the step (1), and mechanically stirring for 2 hours under an ultrasonic condition to obtain a uniformly dispersed solution of bisphthalonitrile and carbonyl iron powder;
(3) placing the uniform dispersion liquid obtained in the step (2) into a three-neck flask, mechanically stirring and refluxing for 4 hours at the temperature of 200 ℃ to obtain a bisphthalonitrile prepolymer solution containing carbonyl iron powder, naturally cooling to room temperature, pouring into deionized water for precipitation and filtration, and washing with the deionized water and absolute ethyl alcohol for 5 times respectively to obtain a green powder prepolymer;
(4) putting 37.5g of the green powder obtained in the step (3) into a three-necked bottle, adding 40mL of 1-4 dioxane and 10mL of N, N-dimethylformamide, heating and stirring at 70 ℃ for 2h to obtain a dark green colloid, and cooling to room temperature for later use;
(5) and (3) placing the colloid pre-polymerized in the step (4) in a tray, and simultaneously soaking the treated 6 pieces of aramid 1313 fiber cloth (20cm multiplied by 20cm) (the total mass is about 37.5g) in the colloid liquid for full immersion. Airing the soaked prepreg fiber cloth at room temperature for 24 hours in a layer to volatilize the solvent to obtain green prepreg fiber cloth; and then drying the cloth in an oven at 180 ℃ for 5min to finally obtain the blackened prepreg fiber cloth.
(6) And (4) cutting and laying the prepreg fiber cloth dried by the solvent in the step (5), placing the prepreg fiber cloth in a grinding tool coated with a release agent, and pressing and molding the prepreg fiber cloth on a hydraulic press. The pressing process comprises the following steps: standing at 200 deg.C for 5min, adding 5MPa pressure, releasing pressure, and repeating for three times. The pressure was then adjusted to 10MPa, released three times repeatedly to remove air and solvent from the prepreg interlayer, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
The cross-sectional scanning electron microscope image of the obtained bi-phthalonitrile/carbon-based iron powder/aramid fiber 1313 fiber cloth three-component composite material is shown in figure 1. FIG. 1 shows that the cross-section is ragged and the fiber surface is rough and uneven, which can absorb more energy when the material breaks; meanwhile, as can be seen from fig. 1, the resin and the fiber have better interface cohesiveness, and the composite material has excellent mechanical properties (the tensile strength and the tensile modulus are 510MPa and 9.8GPa respectively). The maximum reflection intensity of the obtained bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material on electromagnetic waves is only-4.2 dB, as shown by a curve S-0 in the attached figure 4.
Example 2
(1) Dissolving 25g of bisphthalonitrile resin monomer in 500mL of N-methyl pyrrolidone to obtain a bisphthalonitrile solution with the concentration of 50 mg/mL;
(2) adding 25g of carbonyl iron powder into the bisphthalonitrile solution obtained in the step (1), and mechanically stirring for 2 hours under an ultrasonic condition to obtain a uniform dispersion solution of bisphthalonitrile and carbonyl iron powder;
(3) placing the uniform dispersion liquid obtained in the step (2) into a three-neck flask, mechanically stirring and refluxing for 4 hours at the temperature of 200 ℃ to obtain a bisphthalonitrile prepolymer solution containing carbonyl iron powder, naturally cooling to room temperature, pouring into deionized water for precipitation and filtration, and washing with the deionized water and absolute ethyl alcohol for 5 times respectively to obtain a green powder prepolymer;
(4) putting 50g of the green powder obtained in the step (3) into a three-necked bottle, adding 40mL of 1-4 dioxane and 10mL of N, N-dimethylformamide, heating and stirring at 70 ℃ for 2h to obtain a dark green colloid, and cooling to room temperature for later use;
(5) and (3) placing the colloid pre-polymerized in the step (4) in a tray, and simultaneously soaking the treated 6 pieces of aramid 1313 fiber cloth (20cm multiplied by 20cm) (the total mass is about 37.5g) in the colloid liquid for full immersion. Airing the soaked prepreg fiber cloth at room temperature for 24 hours in a layer to volatilize the solvent to obtain green prepreg fiber cloth; and then drying the cloth in an oven at 180 ℃ for 5min to finally obtain the blackened prepreg fiber cloth.
(6) And (4) cutting and laying the prepreg fiber cloth dried by the solvent in the step (5), placing the prepreg fiber cloth in a grinding tool coated with a release agent, and pressing and molding the prepreg fiber cloth on a hydraulic press. The pressing process comprises the following steps: standing at 200 deg.C for 5min, adding 5MPa pressure, releasing pressure, and repeating for three times. The pressure was then adjusted to 10MPa, released three times repeatedly to remove air and solvent from the prepreg interlayer, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
The scanning electron microscope cross-section image of the obtained bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material is shown in figure 2. FIG. 2 shows that the cross-section is ragged and the fiber surface is rough, which can absorb more energy when the material breaks; meanwhile, the resin and the fiber have better interface cohesiveness, and the composite material has excellent mechanical properties (the tensile strength and the tensile modulus are 475MPa and 8.9GPa respectively). The maximum reflection intensity of the obtained bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material on electromagnetic waves is-21.9 dB, and the bandwidth ranges of more than-10 dB are respectively 10.5-14.5 GHz and 15.5-18 GHz, as shown by a curve S-1 in the attached figure 4.
Example 3
(1) Dissolving 25g of bisphthalonitrile resin monomer in 500mL of N-methyl pyrrolidone to obtain a bisphthalonitrile solution with the concentration of 50 mg/mL;
(2) adding 37.5g of carbonyl iron powder into the bisphthalonitrile solution obtained in the step (1), and mechanically stirring for 2 hours under an ultrasonic condition to obtain a uniformly dispersed solution of bisphthalonitrile and carbonyl iron powder;
(3) placing the uniform dispersion liquid obtained in the step (2) into a three-neck flask, mechanically stirring and refluxing for 4 hours at the temperature of 200 ℃ to obtain a bisphthalonitrile prepolymer solution containing carbonyl iron powder, naturally cooling to room temperature, pouring into deionized water for precipitation and filtration, and washing with the deionized water and absolute ethyl alcohol for 5 times respectively to obtain a green powder prepolymer;
(4) putting 62.5g of the green powder obtained in the step (3) into a three-necked bottle, adding 40mL of 1-4 dioxane and 10mL of N, N-dimethylformamide, heating and stirring at 70 ℃ for 2h to obtain a dark green colloid, and cooling to room temperature for later use;
(5) and (3) placing the colloid pre-polymerized in the step (4) in a tray, and simultaneously soaking the treated 6 pieces of aramid 1313 fiber cloth (20cm multiplied by 20cm) (the total mass is about 37.5g) in the colloid liquid for full immersion. Airing the soaked prepreg fiber cloth at room temperature for 24 hours in a layer to volatilize the solvent to obtain green prepreg fiber cloth; and then drying the cloth in an oven at 180 ℃ for 5min to finally obtain the blackened prepreg fiber cloth.
(6) And (4) cutting and laying the prepreg fiber cloth dried by the solvent in the step (5), placing the prepreg fiber cloth in a grinding tool coated with a release agent, and pressing and molding the prepreg fiber cloth on a hydraulic press. The pressing process comprises the following steps: standing at 200 deg.C for 5min, adding 5MPa pressure, releasing pressure, and repeating for three times. The pressure was then adjusted to 10MPa, released three times repeatedly to remove air and solvent from the prepreg interlayer, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
The scanning electron microscope cross-section image of the obtained bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material is shown in figure 3. FIG. 3 shows that the cross-section is ragged and the fiber surface is rough, which can absorb more energy when the material breaks; meanwhile, as can be seen from fig. 3, the resin and the fiber have better interface cohesiveness, and the composite material has excellent mechanical properties (the tensile strength and the tensile modulus are 432MPa and 7.1GPa respectively). The maximum reflection intensity of the obtained bi-phthalonitrile/carbon-based iron powder/aramid 1313 fiber cloth three-component composite material on electromagnetic waves is-29.6 dB, and the bandwidth range of more than-10 dB is 9.2-18 GHz, as shown by a curve S-2 in the attached figure 4.
Claims (11)
1. The preparation method of the electromagnetic microwave shielding composite material is characterized by comprising the following steps of:
a. uniformly mixing carbonyl iron powder and a bisphthalonitrile solution to obtain a uniform dispersion liquid; the mass ratio of the carbonyl iron powder to the bisphthalonitrile is 1.5: 1;
b. stirring the uniform dispersion liquid at 180-220 ℃ for 2-4 h, naturally cooling to room temperature, pouring into deionized water, precipitating, filtering and washing to obtain green powder;
c. mixing the green powder with an organic solvent, stirring for 1-2 hours at 50-70 ℃ to obtain a colloid, and cooling to room temperature; the organic solvent is a mixed solution of 1, 4-dioxane and N, N-dimethylformamide;
d. soaking the aramid fiber 1313 fiber cloth in the colloid, taking out, removing the organic solvent, and performing compression molding to obtain the electromagnetic microwave shielding composite material.
2. A method for preparing an electromagnetic microwave shielding composite material according to claim 1, characterized in that: in the step a, the solute of the bisphthalonitrile solution is bisphthalonitrile, the solvent is N-methylpyrrolidone, and the concentration is 50-200 mg/mL.
3. A method for preparing an electromagnetic microwave shielding composite material according to claim 2, characterized in that: in the step a, the concentration of the bisphthalonitrile solution is 50 mg/mL.
4. A method for preparing an electromagnetic microwave shielding composite material according to any one of claims 1 to 3, characterized in that: in step b, the homogeneous dispersion is stirred at 200 ℃ for 4 h.
5. A method for preparing an electromagnetic microwave shielding composite material according to any one of claims 1 to 3, characterized in that: in the step c, the volume ratio of the 1, 4-dioxane to the N, N-dimethylformamide in the organic solvent is 0.8-0.95: 0.05-0.2.
6. The method for preparing an electromagnetic microwave shielding composite material according to claim 4, characterized in that: in the step c, the mass ratio of the green powder to the organic solvent is 0.8-1.5: 1.
7. A method for preparing an electromagnetic microwave shielding composite material according to any one of claims 1 to 3, characterized in that: in the step d, the following operation is adopted for removing the organic solvent: and (3) airing the soaked prepreg fiber cloth for 20-28 h at room temperature, and then drying the cloth in a drying oven at 150-200 ℃ for 3-5 min to obtain the blackened prepreg fiber cloth.
8. The method for preparing an electromagnetic microwave shielding composite material according to claim 7, characterized in that: and (3) airing the soaked prepreg fiber cloth for 24 hours at room temperature, and then drying the cloth in an oven at 180 ℃ for 5min to obtain the blackened prepreg fiber cloth.
9. The method for preparing an electromagnetic microwave shielding composite material according to claim 7, characterized in that: in the step d, the technological parameters of the compression molding are as follows: standing at 180-220 ℃ for 3-6 min, adding 4-6 MPa of pressure, releasing the pressure, and repeating for three times; then, adjusting the pressure to 8-12 MPa, repeatedly releasing for three times, then applying the pressure to 14-16 MPa, and pressing according to the following procedures: 180-220 ℃/1h, 230-250 ℃/2h, 270-290 ℃/3h and 310-330 ℃/4h to obtain the black and bright plate.
10. A method for preparing an electromagnetic microwave shielding composite material according to claim 9, characterized in that: in the step d, the technological parameters of the compression molding are as follows: standing at 200 deg.C for 5min, adding 5MPa pressure, releasing pressure, and repeating for three times; the pressure was then adjusted to 10MPa, released three times repeatedly, then applied to 15MPa and pressed according to the following procedure: 200 ℃/1h, 240 ℃/2h, 280 ℃/3h and 320 ℃/4h to obtain the black and bright plate.
11. The electromagnetic microwave shielding composite material prepared by the preparation method of the electromagnetic microwave shielding composite material according to any one of claims 1 to 10.
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| CN101700705A (en) * | 2009-06-08 | 2010-05-05 | 电子科技大学 | Thermosetting resin glass fiber laminating composite material and preparation method thereof |
| CN101985352A (en) * | 2010-12-07 | 2011-03-16 | 电子科技大学 | Method for preparing multi-walled carbon nanotubes from phthalocyanine iron polymer by high temperature solid-phase cracking |
| CN102775755A (en) * | 2012-07-31 | 2012-11-14 | 电子科技大学 | Polyaryl ether nitrile (PEN) and carbonyl iron powder (Fe(CO)5) composite magnetic material and preparation method thereof |
| CN106928488A (en) * | 2017-04-11 | 2017-07-07 | 大连理工大学 | Fabric enhancing blending resin base composite laminate of phthalonitrile containing Phthalazinone and preparation method thereof |
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| CN101700705A (en) * | 2009-06-08 | 2010-05-05 | 电子科技大学 | Thermosetting resin glass fiber laminating composite material and preparation method thereof |
| CN101985352A (en) * | 2010-12-07 | 2011-03-16 | 电子科技大学 | Method for preparing multi-walled carbon nanotubes from phthalocyanine iron polymer by high temperature solid-phase cracking |
| CN102775755A (en) * | 2012-07-31 | 2012-11-14 | 电子科技大学 | Polyaryl ether nitrile (PEN) and carbonyl iron powder (Fe(CO)5) composite magnetic material and preparation method thereof |
| CN106928488A (en) * | 2017-04-11 | 2017-07-07 | 大连理工大学 | Fabric enhancing blending resin base composite laminate of phthalonitrile containing Phthalazinone and preparation method thereof |
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