Flexible electromagnetic shielding film material with bionic multilayer structure capable of being regulated into isolation structure and preparation method of flexible electromagnetic shielding film material

Abstract

The invention discloses a flexible electromagnetic shielding film material with a bionic multilayer structure capable of being regulated into an isolation structure and a preparation method of the flexible electromagnetic shielding film material. The flexible electromagnetic shielding film material is prepared by the following steps: sequentially and alternately forming a film from responsive castor oil-based waterborne polyurethane and an electromagnetic shielding filler by utilizing a vacuum suction filtration technology; a multi-layer structure integrated material is formed by hydrogen bonds and electrostatic acting force, and the total thickness is 20-30 microns; in the components of the flexible electromagnetic shielding material, the proportion of the responsive castor oil-based waterborne polyurethane is 97-99 wt%, and the proportion of the electromagnetic shielding filler is 1-3 wt%. The thickness of the flexible electromagnetic shielding film material is only 20-30 [mu] m, a good electromagnetic shielding effect can be obtained, the electromagnetic shielding effectiveness under the X wave band can reach 20-80 dB, the reduction of the electromagnetic shielding effectiveness after the flexible electromagnetic shielding film material is converted into an isolation structure does not exceed 13%, and the electromagnetic shielding film has excellent fire safety performance with low heat release.

Description

technical field [0001] The invention relates to a flexible electromagnetic shielding film material whose bionic multi-layer structure can be adjusted into an isolation structure and a preparation method thereof, belonging to the field of electromagnetic shielding. Background technique [0002] At present, human communication is gradually developing towards the high-frequency band (1-30 GHz) represented by 5G and satellite communication, of which 8.2-12.4 GHz (X-band) plays an important role in communication. It is generally believed that the shielding effectiveness of materials higher than 20dB can meet the general civil needs, while commercial electromagnetic shielding products need to reach at least 30dB. Generally speaking, the efficiency value above 50dB belongs to high electromagnetic shielding material, and the aerospace-grade electromagnetic shielding material is required to reach more than 70dB. Therefore, the traditional metal electromagnetic shielding materials re...

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Problems solved by technology

However, the biomimetic multilayer structure is stable, and once damaged, it is difficult to restore the original state, which leads to the failure of the material's performance.

The polymer matrix selected for common polymer electromagnetic shielding composite materials is thermoplastic polymer material, and the mixed system can be prepared by melting and banburying. Once the thermosetting polymer material with better dimensional stability and comprehensive performance is made into electromagnetic After shielding the composite material, it cannot be processed twice or multiple times, and under the action of external force, such as scratches, broken, and damaged, the electromagnetic shielding performance will drop significantly, and it cannot be repaired or recycled. After the damage, the electromagnetic shielding performance will drop significantly. For the preparation of high High performance and stable thermoset polymer electromagnetic shielding composites cause problems

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