Temperature dependence of the electromagnetic and microwave absorption properties of polyimide/Ti3SiC2 composites in the X band

Ti3SiC2 particles with an average diameter of 5 mm are added into a polyimide matrix to fabricate electromagnetic microwave absorbing materials. The complex permittivity of the composites increases with the increasing Ti3SiC2 content due to an enhanced interface polarization and conduction loss. The maximum reflection loss value of the polyimide/Ti3SiC2 composite is up to -48.6 dB at 8.5 GHz with a thickness of 2.9 mm and the absorption bandwidth below -10 dB is 3.8 GHz. The complex permittivity shows a remarkable temperature dependent effect in the 8.2-12.4 GHz range, and when the temperature is 400 degrees C, the bandwidth below -10 dB is 2.48 GHz with an optimum thickness of 2.0 mm. The excellent absorption properties of the polyimide/Ti3SiC2 composite mean that it can be used as an attractive candidate for a new type of microwave absorption material at elevated temperature.