Experimental study of the dielectric properties of energy-containing materials at variable temperatures

Due to the inherent material characteristics of fireworks and negligent safety management, safety accidents have occurred in recent years, resulting in significant personal and property losses. Therefore, the status inspection of fireworks and other energy-containing materials is a hot issue in the field of energy-containing materials production, storage, transportation, and application. The dielectric constant is a parameter used to characterize the interaction between materials and electromagnetic waves. The methods of obtaining this parameter in the microwave band are not only numerous but also fast and easy. Thus, the real-time status of energy-containing materials can be monitored by monitoring their dielectric properties. Usually, temperature variation has an important effect on the state of energy-containing materials, and the accumulation of temperature can directly cause energy-containing materials to burn or even explode. Based on the above background, this paper proposes a method for testing the dielectric properties of energy-containing materials under variable temperature conditions based on the resonant cavity perturbation theory, which provides important theoretical support for testing the state of energy-containing materials under variable temperatures. Based on the constructed test system, the law of the variation of the dielectric constant of black powder with temperature was obtained, and the theoretical analysis of the test results was carried out. Experimental results show that the temperature change will induce chemical changes in the black powder material, specifically in its dielectric properties, and the magnitude of the changes is large, which is very conducive to real-time monitoring of the black powder state. The system and method developed in this paper can be used to obtain the high-temperature evolution of the dielectric properties of other types of energy-containing materials and provide technical support for the safe production, storage, and application of various types of energy-containing materials.