Attenuation properties of epoxy-Ta2O5 and epoxy-Ta2O5-Bi2O3 composites at γ-ray energies 59.54 and 662 keV

Epoxy resin filled with suitable high Z elements can be a potential shield for X-rays and γ-rays. In this work, we present the γ-ray attenuation properties of epoxy composites filled with (0–30 wt%) Tantalum pentoxide (Ta₂O₅) and Ta₂O₅-Bi₂O_3, which were prepared by open mold cast technique. X-ray diffraction patterns showed crystalline peaks of Ta₂O₅ and bismuth oxide (Bi₂O₃) in the prepared epoxy-Ta₂O₅ and epoxy-Ta₂O₅-Bi₂O₃ composites. Homogeneity of the samples at higher filler wt% was revealed by SEM images. Mechanical characterization showed the enhanced mechanical strength of epoxy-Ta₂O₅-Bi₂O₃ composites compared to epoxy-Ta₂O₅. Higher storage modulus and glass transition temperature of the epoxy-Ta₂O₅-Bi₂O₃ composites showed enhanced stiffness and thermal stability when compared to neat and epoxy-Ta₂O₅. Decrease in the value of tan(δ) at higher content of filler loadings indicated the good adhesion between filler and matrix. Mass attenuation coefficients of epoxy-Ta₂O₅ (30 wt%) composites at γ-ray energies 59.54 and 662 keV were found to be 0.876 cm² g^–1 and 0.084 cm² g^–1, while that of epoxy-Ta₂O₅-Bi₂O₃ (30 wt% Bi₂O₃) composite were 1.271 cm² g^–1 and 0.088 cm² g^–1, respectively. The epoxy-5% Ta₂O₅-30% Bi₂O₃ composites with higher μ/ρ value and tensile strength may be a potential γ-ray shield in various radiation environments.