Polyimide-based sandwich-structure wave absorbing material and preparation method thereof

Abstract

The invention discloses a polyimide-based sandwich-structure wave absorbing material which is of a multifunctional superimposed structure. The polyimide-based sandwich-structure wave absorbing material sequentially comprises a first medium layer, an absorbing layer, a second medium layer and a reflection layer; both the first medium layer and the second medium layer are formed by a quartz fiber reinforced polyimide resin-based composite material, the absorbing layer is formed by a continuous silicon carbide fiber reinforced polyimide resin-based composite material, and the reflection layer is a conducting silver coating. The preparation method comprises the following steps: respectively smearing a polyimide solution onto quartz fiber cloth and silicon carbide fiber cloth to form prepreg; sequentially laying each prepreg in a mould according to the laying sequence and the thickness of each layer, preparing the composite materials by utilizing a thermal molding process, and then thermally treating the composite materials; and finally smearing the conducting silver pulp, and drying to obtain the polyimide-based sandwich-structure wave absorbing material. The polyimide-based sandwich-structure wave absorbing material is high in temperature resisting grade and can resist the high temperature of 350 DEG C or higher; and moreover, the mechanical and wave absorption performances are still excellent under the condition of 350 DEG C.

Description

technical field [0001] The invention relates to the field of wave absorbing materials, in particular to a polyimide-based sandwich structure wave absorbing material and a preparation method thereof. Background technique [0002] At present, the more mature absorbing material structures include Salisbury screen, Dallenbach screen, Jaumman absorber, multi-layer matching structure and so on. Among them, the Salisbury absorber has a narrow absorption frequency band; the Dallenbach absorber is limited by the dispersion effect of the electromagnetic parameters of the current material, and it is difficult to achieve broadband absorption; the Jaumann absorber has a simple design and a wide absorption frequency band, but its main defect is the large thickness of the material; multilayer matching The absorbing material has a wide absorption frequency band, but it is difficult to design, and it is difficult to prepare materials with different dielectric properties. It can be seen that...

AI Technical Summary

Problems solved by technology

Among them, the Salisbury absorber has a narrow absorption frequency band; the Dallenbach absorber is limited by the dispersion effect of the electromagnetic parameters of the current material, and it is difficult to achieve broadband absorption; the Jaumann absorber has a simple design and a wide absorption frequency band, but its main defect is the large thickness of the material; multi-layer matching Absorbing materials have a wide absorption frequency band, but the design is difficult, and it is difficult to prepare materials with different dielectric properties

It can be seen that there are certain deficiencies in the existing absorbing materials.

In addition, from the current research status of structural absorbing materials, the more commonly used method is to add radar absorbers to composite materials to achieve their absorbing properties. The addition of absorbers will lead to adverse effects such as deterioration of mechanical properties of composite materials and increase in density. , and the stability of the material's absorbing performance is difficult to guarantee

[0003] In response to the above problems, ZL200110086529.6 "Silicon carbide fiber-reinforced resin-based sandwich structure absorbing material and its preparation method" reported that high-resistivity silicon carbide fiber cloth was used as the medium layer reinforcement fiber, and low-resistivity silicon carbide fiber cloth was used as the absorbing material. Layer reinforcing fiber, carbon fiber is the reinforcing fiber of the reflective layer, epoxy resin, unsaturated polyester, acrylic resin or phenolic resin is the sandwich structure absorbing material of the resin matrix; the problem existing in this patent is that it needs to be fired separately Silicon carbide fiber, the fiber preparation process is relatively complicated, and the price of silicon carbide fiber is relatively high. A large amount of use leads to high preparation cost, which is not conducive to wide-scale application; patent ZL201110086396.2 "A hybrid fiber reinforced resin-based sandwich structure absorbing Materials and their preparation methods” reported the use of basalt fiber cloth as the medium layer reinforcement fiber, silicon carbide fiber cloth as the absorption layer reinforcement fiber, carbon fiber as the reflection layer reinforcement fiber, epoxy resin, unsaturated polyester, acrylic resin or phenolic resin as the The sandwich structure absorbing material of the matrix; the patent ZL201110086398.1 "Hybrid fiber reinforced resin-based sandwich structure absorbing material and its preparation method" reported that glass fiber cloth was used as the medium layer reinforcement fiber, and silicon carbide fiber cloth was used as the absorption layer reinforcement fiber , Carbon fiber is the reinforcing fiber of the reflective layer, and epoxy resin, unsaturated polyester, acrylic resin or phenolic resin is the sandwich structure absorbing material as the matrix

Patents ZL201110086396.2 and ZL201110086398.1 used low-cost basalt fiber cloth and glass fiber cloth to replace the high-cost silicon carbide fiber cloth used in the dielectric layer in patent ZL200110086529.6, which solved the existing cost problem better, but in the development The temperature resistance level of the resin matrix in the sandwich structure absorbing material is limited, and the strength of the reinforced fiber used is significantly degraded with temperature.

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