Development of Sustainable Radiation-Shielding Blend Using Natural Rubber/NBR, and Bismuth Filler

This research entailed the production of composite materials through the combination of natural rubber and acrylonitrile butadiene rubber, along with nano-silica-loaded bismuth (III) oxide, in varying concentrations ranging from 0 to 45 parts per hundred parts of rubber (phr). The gamma attenuation properties of the composites at different concentrations of Bi2O3 were measured. Additionally, the mechanical properties of the resulting composites, including hardness, tensile strength, and elongation, were tested. The composites with a concentration of 20 phr exhibited the highest tensile strength and elongation at break, followed by a subsequent decrease as the concentration of Bi2O3 increased. The gamma mass-attenuation coefficient of the composites increased as the Bi2O3 concentration increased from 0 to 45 phr, with values ranging from 0.083 to 0.090 cm2/g at 0.662 MeV. Moreover, the fast neutron mass removal cross-sections ranged from 0.092 to 0.072 cm2/g, corresponding to the variation of Bi2O3 concentration from 0–45 phr are also determined. Various parameters related to gamma-ray shielding, including the half-value layer, exposure build-up factor (EBF) up to 40 mean free path (mfp) penetration depth, and effective atomic number (Zeff) are also included. The radiation-induced aging of the prepared blend is tested by measuring the effect of radiation exposure on its shielding capability via its porosity change. The obtained results indicated that the prepared composites could be used for several radiation-protection applications

Gamma Attenuation and Mechanical Characteristics of a Lead/NBR/SBR Rubber Composite with Black Nanocarbon Reinforcement

In this work, black nanocarbon-loaded 0–100 parts-per-hundred (phr) PbO-filled acrylonitrile butadiene rubber (NBR)/styrene-butadiene rubber (SBR) blend composites were prepared by using an ordinary standard rubber mixer. Both mechanical and gamma attenuation properties of the prepared samples were investigated. Maximum tensile strength and elongation at break were obtained at 40 phr PbO concentration. The obtained values for the mass attenuation coefficient with the increased PbO concentration from 0–100 phr ranged from 0.12–0.22 cm2/g at 0.239 MeV. Scanning electron microscope (SEM) with the elemental mapping analysis results showed high homogeneity at 40 phr of the prepared rubber composites, with some areas of elemental agglomeration at a high concentration of lead oxide. The obtained results highly recommend the use of the prepared nanocarbon-reinforced PbO/NBR/SBR blend compared to those previously used as personal protective equipment in radiation-shielding applications