Synthesis and radiation shielding properties of polyimide/Bi₂O₃ composites

Radiation shielding composites based on polyimide and Bi₂O₃ were synthesized. Surface and physical-mechanical properties of polyimide/Bi₂O₃ composites were studied. Bi₂O₃ particles were modified by polymethylphenylsiloxane for the uniform distribution of filler in composites. This paper presents data on the production of composites in two ways: hot- and cold-pressing. The hot-pressing method for the synthesis of composites is preferable compared to the cold-pressing method (the density increases by 10-12%, and the Vickers microhardness by 10-20%). The results show that the introduction of Bi₂O₃ significantly increases the thermal stability of the composites. At 680 °C, a polymer composite containing 10 wt% Bi₂O₃ retains 9.7% of its mass, and at 60 wt% Bi₂O₃, retains 58.4%. The radiation-protective characteristics of the composites with respect to gamma radiation were evaluated by experimental and theoretical methods. High radiation-protective characteristics of the composites have been established in the gamma-quanta energy range of 0.1-1 MeV.