Evaluation of Structure, mechanical, and radiation shielding properties of B ₄ C/PbCl ₂ -reinforced epoxy resin

Abstract

Abstract In the current study, epoxy resin (ER) composites reinforced with 5 wt% boron carbide (B 4 C) and different concentrations of lead chloride (PbCl 2 ) (0–60 wt%) were developed and evaluated for combined γ -ray and neutron shielding applications. X-ray diffraction (XRD) analysis confirmed the amorphous nature of pure ER, characterized by a broad hump near 15°, while the appearance of additional peaks after filler incorporation verified the presence of crystalline B 4 C and PbCl 2 phases. Mechanical testing showed that the mechanical response of the composites depended strongly on the PbCl 2 content. The composite containing 40 wt% PbCl 2 (sample S5) exhibited the most balanced mechanical performance, with improved tensile strength and strain compared with pure ER. The γ -ray shielding performance was evaluated using the Phy-X/PSD software in the energy range of 10 −3 –15 MeV. The mass attenuation coefficient (MAC) increased with increasing PbCl 2 content; at 0.662 MeV the MAC values increased from 0.0815 cm 2 g −1 for pure ER (S1) to 0.09425 cm 2 g −1 for S7 (5% B 4 C/60% PbCl 2 /ER). Correspondingly, the half-value layer (HVL) and mean free path (MFP) decreased with increasing PbCl 2 content, indicating enhanced photon attenuation. Neutron shielding analysis showed a significant improvement in thermal neutron absorption with filler incorporation, where a 1 cm thickness of the composite containing 60 wt% PbCl 2 attenuated over 99.6% of the incident thermal neutron flux. Overall, the results demonstrate that the incorporation of B 4 C and PbCl 2 into epoxy provides composites with improved radiation attenuation while maintaining acceptable mechanical performance, making them candidates for shielding applications in nuclear facilities, medical radiation environments, and radioactive waste management.