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Preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves

An electromagnetic wave and foam technology, which is applied in the field of preparation of wave-absorbing foam, can solve the problem of low absorption performance of wave-absorbing foam, achieve good absorption effect, reduce density, and reduce weight

Inactive Publication Date: 2020-01-03
NO 33 RES INST OF CHINA ELECTRONICS TECHNOOGY GRP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In order to overcome the deficiencies in the prior art, the present invention provides a method for preparing a wave-absorbing foam for low-frequency electromagnetic wave absorption. On the premise of keeping the thickness of the wave-absorbing foam thin and wide-band absorption, the focus is on solving the problem of the wave-absorbing foam in the low-frequency region. The problem of poor absorption performance

Method used

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  • Preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves
  • Preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves
  • Preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves

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preparation example Construction

[0038] Such as figure 1 Shown, a kind of preparation method for the wave-absorbing foam of low-frequency electromagnetic wave absorption, comprises the following steps:

[0039] S1. Mix graphene oxide powder, carbonyl iron powder, and water-based polyurethane emulsion evenly to obtain microwave-absorbing slurry A. The SEM image of microwave-absorbing slurry A is as follows figure 2 shown;

[0040] S2. After fully impregnating the first flexible polyurethane foam in the wave-absorbing slurry A in S1, perform thermal reduction in a Teflon reactor, the thermal reduction temperature is 85-95°C, and the thermal reduction time is 12-15 hours;

[0041] S3. After the reaction is completed, the foam after thermal reduction in S2 is fully rinsed with deionized water, and then dried to obtain a wave-absorbing foam that matches the absorbing layer;

[0042] S4. Mix multi-walled carbon nanotube powder, deionized water, surfactant, and water-based polyurethane emulsion evenly to obtain m...

Embodiment 1

[0050] 1) Mix 8.2 g of graphene oxide (GO) powder, 16.4 g of carbonyl iron powder, and 250 mL of water-based polyurethane emulsion with a solid content of 30% to obtain microwave-absorbing slurry A;

[0051] 2) After fully impregnating the flexible polyurethane foam with a size of 180 mm×180 mm×10 mm in the microwave-absorbing slurry A, transfer it to a Teflon reactor, and heat reduce it at 95 °C for 12 h;

[0052] 3) After the reaction is completed, take the foam out of the Teflon reactor and fully rinse it with deionized water, and then dry it to obtain a wave-absorbing foam that matches the absorbing layer;

[0053] 4) Mix 12.5 g of multi-walled carbon nanotubes, 400 mL of deionized water, 3.8 g of sodium dodecylsulfonate, and 100 mL of water-based polyurethane emulsion with a solid content of 30% to obtain microwave-absorbing slurry B;

[0054] 5) After fully impregnating the flexible polyurethane foam with a size of 180 mm×180 mm×10 mm in the absorbing slurry B, dry it to...

Embodiment 2

[0057] 1) Mix 8.2 g of graphene oxide (GO) powder, 8.2 g of carbonyl iron powder, and 250 mL of water-based polyurethane emulsion with a solid content of 30% to obtain wave-absorbing slurry A;

[0058] 2) After fully impregnating the flexible polyurethane foam with a size of 300 mm×300 mm×10 mm in the microwave-absorbing slurry A, transfer it to a Teflon reactor, and heat reduce it at 85 °C for 15 h;

[0059] 3) After the reaction is completed, take the foam out of the Teflon reactor and fully rinse it with deionized water, and then dry it to obtain a wave-absorbing foam that matches the absorbing layer;

[0060] 4) Mix 12.5 g of multi-walled carbon nanotubes, 400 mL of deionized water, 4 g of carbon nanotube water-based dispersant (TNWDIS), and 50 mL of water-based polyurethane emulsion with a solid content of 30% to obtain microwave-absorbing slurry B;

[0061] 5) After fully impregnating the flexible polyurethane foam with a size of 300 mm×300 mm×10 mm in the absorbing slur...

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Abstract

The invention relates to the technical field of preparation of wave-absorbing materials, particularly to a preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves.The preparation method comprises the following steps: compounding flexible polyurethane foam with obtained reduced graphene oxide / carbonyl iron foam or hydroxylated carbon nanotube / carbonyl iron foamslurry through an impregnation process, and further carrying out thermal reduction to obtain an upper matching absorption layer; and compounding flexible polyurethane foam with aqueous carbon nanotubeslurry or low-defect graphene through an impregnation process to obtain a lower reflection absorption layer, and bonding the lower reflection absorption layer with the upper matching absorption layerto the form final wave-absorbing foam. The influence of process parameters on the structure and performance of the wave-absorbing foam is studied in the invention. On the premise that low thickness and broadband absorption of the wave-absorbing foam are maintained, the problem that the wave-absorbing foam is not high in absorption performance in an L waveband (1-2 GHz) is mainly solved.

Description

technical field [0001] The invention relates to the technical field of preparation of wave-absorbing materials, and more specifically, relates to a preparation method of wave-absorbing foam for low-frequency electromagnetic wave absorption. Background technique [0002] With the continuous development of human society, people have more and more needs for life convenience, informatization and intelligence, which has greatly promoted the development of electronic communication technology, computer technology and radar technology. Then there are many problems such as electromagnetic safety and electromagnetic radiation pollution. Especially in the fields of computer, radar communication, etc., the influence of external electromagnetic radiation, electromagnetic interference between equipment, and interference between electronic devices inside the equipment seriously affect the normal transmission of signals and the normal operation of equipment. Therefore, eliminating clutter ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B32B38/08B32B38/00B32B38/16C08J9/42C08L75/04C08K3/04C08K3/18H05K9/00
CPCB32B38/0036B32B38/08B32B38/162B32B38/164B32B2250/22B32B2266/0278C08J9/42C08J2375/04C08J2475/04C08K3/18C08K3/041C08K3/042H05K9/0081
Inventor 张捷李克训马江将王蓬王东红马晨
Owner NO 33 RES INST OF CHINA ELECTRONICS TECHNOOGY GRP
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