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Efficient electromagnetic shielding composite material and preparation method thereof

An electromagnetic shielding, composite material technology, applied in the fields of magnetic/electric field shielding, electrical components, climate change adaptation, etc., can solve the problems of unfavorable processing, poor electrical conductivity, only 12dB, etc., to achieve enhanced electromagnetic shielding performance, high electromagnetic shielding performance , Enhance the effect of multiple reflections

Active Publication Date: 2019-12-13
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Common metal conductive materials are nano-silver and copper. Among them, the epoxy electromagnetic shielding material of nano-silver powder as a conductive material has obtained satisfactory shielding performance in the high-frequency stage, but the cost of silver is too high, and copper is low in cost, but metal The oxidation resistance of copper is slightly poor, which leads to poor conductivity stability, which limits the wide application of copper
Common carbon nanofillers include graphene, carbon black, carbon nanotubes, etc. Among them, the epoxy composite material with graphene has better electromagnetic shielding performance, but the cost is too high, and the epoxy composite material with carbon black has poor electromagnetic shielding performance
[0006] Carbon nanotubes (CNTs) have excellent elastic modulus, electrical conductivity and thermal conductivity, but the electromagnetic shielding performance of epoxy composites simply adding carbon nanotubes (CNTs) is not satisfactory, for example, Yu Chen et al., "High-Performance Epoxy Nanocomposites Reinforced with Three-Dimensional CarbonNanotube Sponge for Electromagnetic Interference Shielding", reported that adding up to 10% carbon nanotubes to epoxy resin composites, but its electromagnetic shielding performance is only 12dB, which needs further improvement
[0007] Since the addition of carbon nanotubes has a great influence on the fluidity of the system, adding too much will increase the cost, is not conducive to processing, and will also deteriorate the mechanical properties of the composite material

Method used

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  • Efficient electromagnetic shielding composite material and preparation method thereof
  • Efficient electromagnetic shielding composite material and preparation method thereof
  • Efficient electromagnetic shielding composite material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Embodiment 1, the preparation of the high-efficiency electromagnetic shielding composite material of the present invention

[0049] According to the feed ratio shown in Table 1, the inventive high-efficiency electromagnetic shielding composite material is prepared, and the specific steps are as follows:

[0050] Carbon nanotube powder (MWCNT) was dispersed in dichloromethane and sonicated for 0.5 h to form a homogeneous suspension. Subsequently, polyethersulfone PES was added to the above MWCNT suspension and stirred to dissolve. Then epoxy resin E51 and curing agent MOCA were added and stirred for 0.5 hours to achieve uniform dispersion. Then the above mixture was uniformly stirred at 60° C. for 4 hours, and then dried in a vacuum oven at 70° C. for 24 hours to remove residual dichloromethane. Finally, the resulting system was poured into a mold, cured at 150°C for 4 hours, and then cured at 180°C for 2 hours to obtain high-efficiency electromagnetic shielding compos...

experiment example 1

[0056] Experimental example 1. SEM quenching test of high-efficiency electromagnetic shielding composite materials

[0057] (1) Experimental method

[0058] Quenching cross-sectional scanning electron microscopy: JEOL JSM 5900 field emission scanning electron microscopy (FESEM) was used to observe the microscopic morphology of the composites. To observe the morphology of the epoxy blends, the samples were brittle broken in liquid nitrogen. The samples were vapor-deposited with gold vapor for 15 s before observation.

[0059] SEM of the quenched section after being etched by dichloromethane: 25phrPES-3phrCNT and 30phrPES-3phrCNT etched samples were soaked in dichloromethane for 3 hours to obtain the etched section after brittle fracture. The samples were vapor-deposited with gold vapor for 15 s before observation.

[0060] (2) Experimental results

[0061] Such as figure 1 As shown in a, the blend of 30phrPES sample before curing is homogeneous and transparent at 150 °C, a...

experiment example 2

[0066] Experimental example 2. Magnetic shielding performance test of high-efficiency electromagnetic shielding composite materials

[0067] (1) Experimental method

[0068] The electromagnetic shielding effect of each sample was measured in the frequency range of 8.2–12.4 GHz using an Agilent N5230 vector network analyzer, which was calibrated with standard APC-7 connector open, short, and 50Ω loads. A sample with a thickness of 2 mm and a diameter of 12 mm was placed in a sample holder and connected to a separate VNA port via an Agilent 85132F coaxial cable.

[0069] (2) Experimental results

[0070] The result is as Figure 4 As shown, it can be seen that compared with 3phrCNT, the average electromagnetic shielding effectiveness of 25phrPES-3phrCNT and 30phrPES-3phrCNT in the X-band is significantly improved, from 14.3dB to 21.6dB and 21.8dB, respectively. It shows that compared with the composite material only adding carbon nanotubes, the present invention adds carbon n...

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Abstract

The invention provides an efficient electromagnetic shielding composite material. The efficient electromagnetic shielding composite material is prepared from, by weight, 10.0 parts of an epoxy resin,2.0-5.0 parts of a curing agent, 2.0-6.0 parts of a thermoplastic polymer and 0.2-1.0 part of a one-dimensional conductive nanofiller with a high aspect ratio. The addition amount of the carbon nanotubes into the efficient electromagnetic shielding composite material is as low as 3 wt%, but the electromagnetic shielding performance of the composite material obtained under the synergistic action ofthe nanotubes and the thermoplastic polyethersulfone is as high as 21.8 dB. Compared with like products in the prior art, the composite material prepared in the invention achieves a higher electromagnetic shielding performance under a lower addition amount of the carbon nanotubes. The efficient electromagnetic shielding composite material prepared in the invention has very good application prospects in the fields of space flight and aviation, communication electronics and human body protection.

Description

technical field [0001] The invention belongs to the field of polymer modified materials, and in particular relates to a high-efficiency electromagnetic shielding composite material and a preparation method thereof. Background technique [0002] As we all know, any electronic equipment that transmits, distributes or uses electric energy will generate electromagnetic interference, which will adversely affect the performance of the equipment and the surrounding environment. With the rapid development of modern communication and electronic technology in recent years, electronic equipment has become more and more intelligent and volume The smaller the size, the sharper the use of electronic equipment, and the resulting increase in electromagnetic interference (EMI), which will lead to equipment failure and aging of electronic components, and will also affect human health and the surrounding environment. Therefore, certain measures need to be taken to reduce the harm of electromag...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08L63/00C08L81/06C08K3/04H05K9/00
CPCC08L63/00H05K9/0081C08K2201/011C08K2201/003C08K2201/004C08K2201/006C08K2201/001C08L2203/20C08L81/06C08K3/041Y02A30/00
Inventor 邹华维张浩若陈洋衡正光周勣梁梅
Owner SICHUAN UNIV