Analysis of Load-Bearing Electrical Properties of Composite Materials Based on Homogenization Theory

Abstract

In this study, the broadband dielectric spectrum of polyimide composites was examined using the homogenization theory. The findings demonstrate that the addition of boron nitride nanosheets (BNNSs) and silver nanoparticles (AgNPs) causes an increase in conductivity, dielectric constant, and dielectric loss of the composites but does not result in a surge in the three parameters; the results also demonstrate that an increase in temperature causes an increase in dielectric constant and dielectric loss of the composites. In addition, temperature has a bigger impact on the dielectric loss than it does on the dielectric constant. An increase in the amount of polarized charges and a shallower bulk trap depth can result from the addition of nanomaterials, according to research on thermally stimulated current in composite materials. The presence of the interfacial region, which made it simple to cause charge accumulation and simple to form conduction current, is primarily responsible for the significant increase in bulk conductivity of the composites at 50 Hz that occurred with the addition of more nanomaterials. The large rise in bulk conductivity of the composites at 50 Hz that happened with the addition of more nanomaterials is mostly due to the existence of the interfacial region, which made it simple to produce charge buildup and simple to form conduction current. The variation in volume conductivity when the doping ratio is less than 10 vol% is not significant due to AgNPs’ low concentration and ambiguous contribution to the conduction current. As the polarization temperature rises, the amount of polarization charges increases, but it has minimal effect on the bulk trap depth of the composites.