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A modified polyimide based microwave absorbing material for microwave anechoic chambers, absorbing structure and preparation method thereof

A polyimide-based, microwave anechoic chamber technology, applied in the field of microwave-absorbing materials, to achieve the effect of improving heat insulation, good sound insulation performance, and maintaining a constant temperature

Active Publication Date: 2021-07-23
贵州航天建设工程有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above patents either only use a single absorbing medium, or only improve the absorbing pyramid
At present, a kind of absorbing material with excellent comprehensive performance and high absorption rate for electromagnetic waves and sound waves has not yet been obtained.

Method used

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  • A modified polyimide based microwave absorbing material for microwave anechoic chambers, absorbing structure and preparation method thereof
  • A modified polyimide based microwave absorbing material for microwave anechoic chambers, absorbing structure and preparation method thereof
  • A modified polyimide based microwave absorbing material for microwave anechoic chambers, absorbing structure and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] 1) Preparation of polyimide foam precursor composite absorbing material absorbing pyramid

[0048] In parts by mass, 85% polyimide foaming precursor, 0.2% tetrahydrofuran, 8% modified carbon nanotubes, 2.8% magnetic iron nanomaterials, 4% retinyl Schiff alkali metal Salt complexes, 100% in total, are fully mixed and dried, placed in a pyramidal foaming mold with a first preheating temperature of 80°C for 0.5h, and then the temperature is raised to the second foaming temperature of 140°C, and kept warm 3h; then raise the temperature to the third imidization temperature of 300°C, and keep it warm for 2h; after the warming is over, lower it to room temperature, and then prepare a polyimide foaming precursor composite wave-absorbing material wave-absorbing pyramid.

[0049] 2) Preparation of modified aluminum foam

[0050]In parts by mass, 90% of aluminum powder, 4% of modified carbon nanotubes, 3% of magnetic iron nano-magnetic beads, 1% of silicon carbide, and 2% of tita...

Embodiment 2

[0054] 1) Preparation of polyimide foam precursor composite absorbing material absorbing pyramid

[0055] In parts by mass, 88% polyimide foaming precursor, 0.5% tetrahydrofuran, 2.5% modified carbon nanotubes, 6% magnetic iron nanomaterials, 3% retinyl Schiff alkali metal Salt complexes, 100% in total, are fully mixed and dried, placed in a pyramidal foaming mold with the first preheating temperature of 85°C for 0.4h, then raised to the second foaming temperature of 142°C, and kept warm 2.7h; then raise the temperature to the third imidization temperature of 305°C, and keep it warm for 1.8h; after the heat preservation is over, lower it to room temperature, and then prepare a polyimide foaming precursor composite wave-absorbing material absorbing pyramid .

[0056] 2) Preparation of modified aluminum foam

[0057] In parts by mass, 91% of aluminum powder, 3% of modified carbon nanotubes, 1.5% of magnetic iron nano-magnetic beads, 3% of silicon carbide, and 1.5% of titanium ...

Embodiment 3

[0061] 1) Preparation of polyimide foam precursor composite absorbing material absorbing pyramid

[0062] In parts by mass, 93% polyimide foaming precursor, 0.8% tetrahydrofuran, 5.6% modified carbon nanotubes, 0.5% magnetic iron nanomaterials, 0.1% retinyl Schiff alkali metal Salt complexes, 100% in total, are fully mixed and then dried, placed in a pyramidal foaming mold with a first preheating temperature of 95°C for 0.2h, then raised to the second foaming temperature of 145°C, and kept warm 2.5h; then raise the temperature to the third imidization temperature of 315°C, and keep it warm for 1.5h; after the heat preservation is over, lower it to room temperature, and then a polyimide foaming precursor composite wave-absorbing material wave-absorbing pyramid is prepared. .

[0063] 2) Preparation of modified aluminum foam

[0064] In terms of parts by mass, 93% of aluminum powder, 2.5% of modified carbon nanotubes, 2% of magnetic iron nano-magnetic beads, 1.5% of silicon ca...

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Abstract

A microwave absorbing material for microwave anechoic chamber based on modified polyimide is composed of polyimide foam precursor composite absorbing material and modified aluminum foam; polyimide foam precursor composite absorbing material material to make a wave-absorbing pyramid, and the wave-absorbing pyramid is adhered to a modified aluminum foam board through an adhesive, and the other side of the modified foamed aluminum board is fixed with a foamed aluminum board by long nails, and the modified foamed aluminum board and the foam There are voids between the aluminum plates, which are filled with airgel. The beneficial effect lies in: using a variety of wave-absorbing medium materials to form a wave-absorbing pyramid, effectively improving the wave-absorbing performance of the composite material at each frequency; It has excellent sound insulation performance; airgel is used to fill the interlayer between modified aluminum foam and ordinary aluminum foam, which improves the heat insulation performance.

Description

technical field [0001] The invention belongs to the field of wave-absorbing materials, and relates to a wave-absorbing material for a microwave darkroom based on a modified polyimide group, a wave-absorbing structure and a preparation method thereof. Background technique [0002] The microwave anechoic chamber is to use absorbing materials to create a closed space, create a pure electromagnetic environment, and eliminate external electromagnetic interference. It is a place for testing wireless communication products and electronic products such as antennas and radars. The test products can be free from clutter interference. Improve the test accuracy and efficiency of the device under test. At present, microwave anechoic chambers mostly use ferrite magnets / expanded polystyrene, ferrite / expanded polypropylene, etc. as absorbing pyramid materials, and the materials are mostly B2 flame-retardant materials, which are not safe. At the same time, the absorbing performance of a sin...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B32B15/08B32B15/20B32B27/28B32B9/00B32B9/04B32B7/08B32B7/12B32B3/30B32B37/12B32B37/00C08L79/08C08K13/06C08K9/02C08K3/04C08K3/22C08K5/00C08J9/00H05K9/00
CPCB32B3/30B32B5/18B32B5/20B32B5/245B32B7/08B32B7/12B32B37/12B32B2250/22B32B2266/0214B32B2266/045B32B2307/102B32B2307/212B32B2307/306B32B2307/3065B32B2266/126C08J9/0014C08J9/0066C08J9/009C08J9/0095C08J2379/08C08K3/22C08K5/0091C08K9/02C08K13/06C08K2003/2275C08K2201/01C08K2201/011C08K3/041H05K9/0081H05K9/0083
Inventor 罗正权胡渊李英章伍鑫杨云鹏夏林灿骆金科王建李怀柱黄春洪伍小季朱伟官忠臣杨军李小东朱宇翔朱丽娟梁鹏志
Owner 贵州航天建设工程有限公司
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