Enhanced X-ray shielding performance of HDPE–Sb₂O₃ composites in the diagnostic dental X-ray energy range

Developing lightweight, efficient radiation shielding materials remains a critical challenge for diagnostic X-ray applications. In the present work, high-density polyethylene (HDPE) composites reinforced with different concentrations of antimony oxide (Sb₂O₃) were investigated as potential alternatives to conventional radiation shielding materials. The present study specifically aimed to evaluate the effect of Sb₂O₃ loading on the low-energy X-ray shielding performance and material characteristics of HDPE composites. The composites were prepared using melt-mixing and hot-pressing techniques with Sb₂O₃ additives of 5–15 wt%. Then, experimental measurements were conducted over 50–150 kVp, whereas computational simulations were performed at discrete photon energies of 32.5–64.5 keV. Moreover, radiation attenuation parameters such as the linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), half-value layer (HVL), and mean free path (MFP) were examined together with density, mechanical, thermal, and microstructural characteristics, and complemented by Monte Carlo simulations (GEANT4, MCNPX) and XCOM calculations. The obtained results showed an improvement in attenuation efficiency with increasing Sb₂O₃ content. Moreover, the sample containing 15 wt% Sb₂O₃ content exhibited the highest shielding performance across all studied energy levels. The onset degradation temperature increased from 446.3 °C for neat HDPE to 464.8 °C for the 15 wt% Sb₂O₃ composite, while the tensile strength changed from 24.97 ± 1.71 MPa to 23.91 ± 1.31 MPa. These improvements are attributed to an increased effective atomic number and density, along with an enhanced photon interaction probability, particularly under photoelectric-dominated regimes. Overall, the findings indicate that Sb₂O₃ incorporation can enhance the low-energy X-ray attenuation of HDPE while maintaining comparable tensile strength and improving thermal stability, supporting further investigation of these composites as lightweight shielding materials for diagnostic X-ray applications.