How to reduce the surface resistance of magnetic loaded rubber absorbing materials to minimize electromagnetic wave reflection?

In the development of modern technology, the electromagnetic environment is becoming increasingly complex, and the importance of absorbing materials is becoming increasingly prominent. Magnetic loaded rubber absorbing materialDue to its excellent flexibility and absorption performance, it has been widely used in many fields. However, high surface resistance of materials can lead to increased electromagnetic wave reflection and reduced absorption effect. Therefore, exploring methods to reduce its surface resistance is of great significance for improving material properties.

Optimize the selection and addition of conductive fillers

Select highly conductive fillers

Conductive fillers are one of the key factors in reducing the surface resistance of materials. For example, adding highly conductive materials such as graphene and carbon nanotubes to magnetic loaded rubber can significantly improve the conductivity of the material. Graphene has excellent two-dimensional planar structure and ultra-high conductivity, and its unique π - electron cloud structure can efficiently transfer electrons. When an appropriate amount of graphene is uniformly dispersed in the rubber matrix, a continuous conductive network can be formed, significantly reducing the surface resistance of the material. Research has shown that adding 2% -5% mass fraction of graphene can reduce the surface resistance of magnetic loaded rubber to 1/10-1/5 of its original value.

Control the particle size and shape of fillers

In addition to the type, the particle size and shape of conductive fillers also have an impact on surface resistance. Fillers with smaller particle sizes can provide more contact points and promote electronic conduction. For example, nanoscale carbon black is more effective in reducing surface resistance than micrometer scale carbon black. Meanwhile, fibrous or sheet-like fillers, such as carbon nanotubes and graphene, are more likely to form conductive pathways in the rubber matrix compared to spherical fillers, further reducing surface resistance. By reasonably combining conductive fillers of different particle sizes and shapes, a more complete conductive network can be constructed to reduce electromagnetic wave reflection.

Improve the preparation process of materials

Enhance mixing uniformity

It is crucial to ensure that the conductive filler is thoroughly and uniformly mixed with the rubber matrix during the preparation process. The use of advanced mixing equipment, such as twin-screw extruders, can improve mixing efficiency and uniformity. During the twin-screw extrusion process, the material is efficiently dispersed under the shear and extrusion action of the screw, allowing the conductive filler to be evenly distributed in the rubber matrix, reducing agglomeration and forming a more stable conductive network, thereby reducing surface resistance. Compared to traditional open mill mixing, the surface resistance of magnetic loaded rubber absorbing materials prepared by twin-screw extruder can be reduced by about 30%.

Optimize vulcanization process

The vulcanization process has a significant impact on the microstructure and properties of materials. Appropriate vulcanization temperature and time can achieve moderate crosslinking degree of rubber molecular chains, which is beneficial for the stability of the conductive network while ensuring the mechanical properties of the material. If the vulcanization temperature is too high or the time is too long, the rubber molecular chains may crosslink excessively, which may damage the conductive network formed by the conductive filler and lead to an increase in surface resistance. Research has found that by controlling the vulcanization temperature at 150-160 ℃ and the vulcanization time at 15-20 minutes, the prepared Magnetic loaded rubber absorbing materialThe surface resistance is low and the absorption performance is good.

Introducing surface treatment technology

Conductive coating treatment

Coating a conductive layer on the surface of magnetic loaded rubber is a direct method to reduce surface resistance. If chemical plating or electroplating is used to deposit a layer of metal (such as copper, silver, etc.) coating on the surface of the material. Metals have good conductivity, which can effectively reduce surface resistance and minimize electromagnetic wave reflection. Chemical copper plating coating can reduce the surface resistance of the material to below 10 Ω/sq, significantly improving the material's ability to absorb electromagnetic waves.

Plasma treatment

Plasma treatment can introduce active groups on the surface of materials, improve surface properties, promote the bonding between conductive fillers and rubber matrix, and optimize the conductive network. After plasma treatment, the surface roughness of magnetic loaded rubber increases, which is conducive to the adhesion and dispersion of conductive fillers, thereby reducing surface resistance. For example, by using radio frequency plasma treatment for 5-10 minutes, the surface resistance of the material can be reduced by 10% -20%.

reduce Magnetic loaded rubber absorbing materialThe surface resistance can be achieved through various methods such as optimizing conductive fillers, improving preparation processes, and introducing surface treatment techniques. These methods, when combined with each other, can effectively reduce electromagnetic wave reflection, improve the absorption performance of materials, and provide strong support for their widespread application in fields such as electromagnetic protection and stealth technology. In practical applications, it is necessary to comprehensively select appropriate methods based on specific needs and material characteristics to achieve the best results.