Effects of Gamma Irradiation on the Dielectric Properties of Polypropylene-Based Composites

This work investigates the effect of gamma irradiation on the dielectric properties of polypropylene/α SiO2 nanocomposites. The non-polar nature of polypropylene has allowed it to be used as an insulating material. At the same time, this property makes polypropylene a suitable matrix for nanoparticle-filled composites. In the study, the PP + αSiO2 composite was obtained by melt mixing at a temperature of 170−190 °C, and then samples were prepared from it by pressing, and the thickness of the prepared samples was 90 µm. The resulting composites were irradiated with gamma rays. Then, the effect of absorbed dose on the electrophysical parameters of composite samples after irradiation was studied. During the study, a comparative analysis of the electrophysical parameters of non-irradiated and irradiated samples was conducted. It was found that the resulting nanocomposites increase the absorption of electromagnetic waves. As the absorbed dose of radiation increases, the degree of crystallization of the material decreases, the crystalline structure gradually disintegrates, and at high doses it completely disappears. The value of ɛ increases significantly at the beginning and remains constant at subsequent values of dose increase, leading to a sharp increase in dielectric losses.