Electromagnetic shielding material with a three-layer structure and preparation method thereof

The invention discloses an electromagnetic shielding material with a three-layer structure and a preparation method thereof. The electromagnetic shielding material is composed of carbon nanotubes andpolypropylene. The polypropylene/carbon nanotube composite material with different contents of carbon nanotubes is obtained by adopting a physical blending method, and is subjected to hot press molding on a press vulcanizer to obtain a strip sample with a three-layer structure and having a high carbon nanotube content in the skin layers and a low carbon nanotube content in the core layer; finallythe strip sample is put into a high-temperature and high-pressure reaction kettle, and a three-section temperature control type intermittent foaming method is adopted to prepare a polypropylene/carbonnanotube material with a three-layer foam structure, which has basically non-foamed upper and lower skin layers and a foamed middle core layer. The preparation method can reduce the mass of the electromagnetic shielding materi