Composite materials based on polymer fillers have been intensively studied in recent years, and in many cases, polymer nanocomposites find new applications in the preparation of certain sensors (recorders), surface coatings of spacecraft, especial type of the sensors. In addition, it is known that the change in the size of the fillers, the resistance of the composite materials to the influence of various types of radiation (ℽ-rays, electron, e-rays, ultraviolet rays, etc.), electrical conductivity, etc.), the study of which is still relevant today, and occupies a large place in radiation materials science. It can be noted that composite materials consisting of polymer - nanoscale fillers occupy a key place in many global research centers of the world. The purpose of the work is to obtain and study new electroactive (electret, antistatic, radiation-sensitive) polymer composite materials. Polypropylene was used as binder and ????????2????3 oxide as filler in this work. In other research works, the sizes of the oxide fillers were large. In this study, nanofillers were used. Experiments show that as the size of oxide particles decreases, its electret properties improve. At the same time, the relaxation process of electret charges of polymer composites also depends on the value of the initial irradiation dose of ????-rays. As a result of studying the relaxation ????-, ????- and ????- processes of ????????⁄???? - ????????2????3 composites in the temperature range of 100 ÷ 500 K by the radio-thermoluminescence (RTL) method, it was determined that the maximum at T = 230 K, the observed luminescence peak from the filler concentration ((20÷40) % ???? - ????????2????3) and varies proportionally depending on the radiation dose, and it can be used as a dosimeter in γ-dosimetry at a dose rate of up to 50 kGr.