Preparation and Application of Carbon Fiber/Resin Composite Absorbing Materials

 

1. Brief Introduction of the Results

Absorbing materials, also known as radar absorbing materials (RAM), refer to a type of material that can absorb and attenuate incident electromagnetic waves, and convert their electromagnetic energy into heat energy and consume it or make the electromagnetic waves disappear due to interference.

 

At present, with the increasing severity of electromagnetic wave pollution, absorbing materials have great development potential in the civilian field. Many studies have shown that continuous, high-intensity electromagnetic wave irradiation can induce cell mutations, tumors, cancer and other diseases. Electromagnetic wave pollution has become one of the key environmental pollutions to be managed by countries around the world in this century.

 

It is impossible to prevent electronic devices from emitting electromagnetic waves, so the most effective way to eliminate electromagnetic wave pollution is to use absorbing materials.

 

This research, which belongs to the category of electromagnetic interference (EMI), has been widely valued and applied in countries around the world.

 

2. Technical Features

 

This research aims to prepare carbon fiber (felt) resin-based composite absorbing materials with different contents and distributions. It mainly studies the influence of carbon fiber (felt) arrangement mode and content on the absorbing performance of the material. By adjusting the parameters, the purpose of broadband, efficient and selective absorption of electromagnetic waves by the material is achieved. Secondly, by modifying the surface of the fiber (felt), adding electromagnetic loss agent, changing the type of matrix, etc., a rigid and flexible matrix absorbing material is prepared. At the same time, the absorbing mechanism is studied in order to develop a low-cost, broadband, efficient and lightweight absorbing material.

 

The sample is prepared by compression molding using a composite material molding process. The epoxy resin and low molecular weight polyamide are mixed evenly in a mass ratio of 2:1 (E-44 epoxy resin: low molecular weight polyamide resin = 100:50~100:100 mass ratio), degassed in a vacuum drying oven, and then poured into a preheated semi-overflow mold with carbon fiber or carbon felt pre-placed in the mold. A layer of S-glass cloth is added on the surface of the wave-transmitting layer to achieve impedance matching with free space. A layer of glass cloth is also added on the bottom of the mold to offset the stress caused by the wave-transmitting layer glass cloth so that the sample does not bend and cause measurement errors.

 

The cast mold is then cured at 60℃ and 10MPa for 2 hours to obtain the required 180mm×180mm, 4mm thick square standard sample.

 

III. Promotion and Application

 

This research result has obtained environmental functional materials with good wave absorption performance and commercial value through a large number of experiments for more than two years. At present, it has been deeply applied to communication anti-interference, environmental protection and human protection, protection against electromagnetic wave pollution, construction of microwave darkrooms and many other fields. It can be used to eliminate harmful electromagnetic waves in the environment space, and the technology is at the international advanced level.