Rubber-Based Flexible Polymer Composite for Radiation Protection with Rare Earth Metal Oxides

Abstract

The description is given to the synthesis of a flexible polymer composite for radiation protection based on a rubber matrix and rare-earth metal oxides (Dy₂O₃ and Gd₂O₃). The physico-mechanical parameters are established for the compositions with dysprosium oxide as follows: the density ranging from 1.31 to 2.44 g/cm³, tensile strength is staying between 6.06 and 1.72 MPa. In contrast, compositions with gadolinium oxide have a density of 1.27–2.40 g/cm³, tensile strength being 5.81–0.93 MPa. The microstructure of the composite surface and cross-section is examined in detail revealing uniform filler distribution. However, adding gadolinium oxide promotes forming agglomerates up to 50 μm in size. Based on experimental data obtained after exposing composite samples to gamma radiation with energies E(²⁰⁷Bi) = 0.570 MeV; E(¹³⁷Cs) = 0.662 MeV; E(⁶⁰Co) = 1.252 MeV), the linear attenuation coefficients (0.251; 0.235; 0.201 cm^–1 for KDy60 and 0.226; 0.214; 0.176 cm^–1 for KGd60) and mass attenuation coefficients (0.102; 0.096; 0.082 cm²/g for KDy60 and 0.094; 0.089; 0.073 cm²/g for KGd60) are calculated. Increasing the filler content enhances radiation-shielding properties, with dysprosium oxide compositions demonstrating superior efficiency.