Preparation method of PMI high-temperature-resistant wave-absorbing material

Abstract

The invention discloses a preparation method of a PMI high-temperature-resistant wave-absorbing material. The preparation method comprises the following eight steps: preparing a PMI prepolymer columnar particle jig; preparing a PMI prepolymer; placing a cavity mold array filled with a mixture in a water bath to obtain a methacrylic acid and methacrylonitrile copolymerized columnar object; granulating by using a granulator to obtain foam-able PMI prepolymer particles; carrying out pre-foaming on the foam-able PMI prepolymer particles; preparing an electromagnetic wave absorbent; preparing PMI wave-absorbing foam particles; and putting the PMI wave-absorbing foam particles into a molding press, and performing film pressing. The wave-absorbing material has the advantages that the wave-absorbing material has good high-temperature resistance and a good electromagnetic wave absorbing performance, and the absorbent can be uniformly mixed in foam.

Description

technical field [0001] The invention relates to the technical field of preparation of wave-absorbing materials, in particular to a method for preparing a PMI high-temperature-resistant wave-absorbing material. Background technique [0002] At present, there are many types of absorbing materials in the market, and they have various functions. However, absorbing materials for special applications are still in short supply. Especially in the current special use environment of aerospace, at least 200° high-temperature use environment is required. Neither wave materials nor high polymer wave absorbing materials can meet this requirement, so high temperature resistant wave absorbing materials have become the research direction at present. The difficulty in the development of PMI wave absorbing materials lies in the addition of wave absorbing agents, because PMI foams are closed cells The structure cannot absorb the wave absorber into the polyurethane cell like the polyurethane ope...

AI Technical Summary

Problems solved by technology

[0002] At present, there are many types of absorbing materials in the market, and they have various functions. However, absorbing materials for special applications are still in short supply. Especially in the current special use environment of aerospace, at least 200° high-temperature use environment is required. Neither wave materials nor high polymer wave absorbing materials can meet this requirement, so high temperature resistant wave absorbing materials have become the research direction at present. The difficulty in the development of PMI wave absorbing materials lies in the addition of wave absorbing agents, because PMI foams are closed cells structure, the absorber cannot be absorbed into the polyurethane cells like the polyurethane open-cell structure, nor can it be mixed with the polymer and the absorber, so the current development of PMI high-temperature absorbing materials is difficult

[0003] At present, some PMI high-temperature resistant wave-absorbing materials on the market directly add electromagnetic wave absorbers to PMI polymers. PMI foams use methacrylic acid and methacrylonitrile as comonomers. Since the monomers are liquids, the absorbers are basically inorganic substances. Materials such as black, graphite, and manganese dioxide. After mixing methacrylic acid and methacrylonitrile monomers, inorganic substances precipitate after stopping stirring, resulting in unsuccessful polymerization or uneven distribution of conductive agents. Phenomenon

Or some technologies use the skinning method on the surface of PMI foam boards to solve the problem of adding absorbents. These are not very good solutions to the problem of adding absorbents to PMI high-temperature resistant wave-absorbing materials.