Polyimide/multi-walled carbon nanotube composite aerogel as well as preparation method and application thereof

Abstract

The invention provides polyimide / multi-walled carbon nanotube composite aerogel as well as a preparation method and application thereof. The aerogel is polymer-based composite aerogel prepared by taking polyimide as a matrix and multi-walled carbon nanotubes as a filler; the mass ratio of the polyimide to the multi-walled carbon nanotubes is 100:(4-16). The polyimide / carbon nanotube composite aerogel disclosed by the invention has an ordered pore structure, low density, excellent electromagnetic wave absorption performance, anisotropy and excellent thermal stability, and has wide application prospects in many important fields such as aerospace, national defense, traffic, medical instruments, microelectronic devices and the like.

Description

technical field [0001] The invention belongs to the field of composite materials, and in particular relates to a polyimide / multi-walled carbon nanotube composite airgel and its preparation method and application. Background technique [0002] With the rapid development of electronic communication technology, the use of electronic communication equipment is becoming more and more common. While these electronic products bring us convenience, the electromagnetic hazards generated during their work are becoming increasingly prominent. Electromagnetic interference affects the normal operation of equipment, and electromagnetic pollution will have adverse effects on the human body and the natural environment. In addition, electromagnetic waves are used as a medium for transmitting information, and its leakage means the leakage of the information it transmits, which will seriously endanger information security. At present, the harm of electromagnetic waves to information security,...

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Problems solved by technology

However, none of the above-mentioned prior art has prepared a composite material with anisotropic ordered pore structure, and failed to endow the material with unique properties.

[0008] Invention patent application CN111607228A discloses a composite aerogel with polyimide as the matrix, multi-walled carbon nanotubes and nano ferric oxide as the filler, which has an anisotropic ordered pore structure, but the types of fillers and The addition amount is high, and in the case of the synergistic effect of carbon nanotubes and nano-ferric oxide, the minimum reflection loss peak value of the material with a thickness of 4mm in the horizontal direction is only -43dB, and the effective absorption bandwidth of the 3mm sample is only 6GHz, and did not explore its absorbing performance in the vertical direction

However, its initial thermal decomposition temperature is only 500°C, and the residual weight at 800°C is only 56% in the case of high filler addition

Therefore, there are still deficiencies in the performance and thermal stability of the airgel with anisotropic pore structure in this patent for absorbing electromagnetic waves

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