Polyvinyl chloride/ styrene butadiene rubber polymeric blend filled with bismuth subcarbonate (BiO)2CO3 as a shielding material for gamma rays

AbstractThe polymer blend polyvinyl chloride/styrene‐butadiene rubber filled of (BiO)2CO3 with different concentrations (20, 30, 40, and 60 phr) were prepared by roll mill technique. The gamma‐rays attenuation properties were carried out using NaI (Tl) gamma ray spectrometer using 232Th. The attenuation coefficients, half value layer and mean free path were evaluated. The distribution of the filler within the polymer matrix was studied using scanning electron microscopy. The prepared polymer composites were characterized by X‐ray diffraction technique to recognize the structural phase of the composites. The hardness and tensile strength of the composites were tested. The tensile strength of the composites was found to be enhanced in the presence of the bismuth subcarbonate filler with a slight decrease when the concentration of the filler exceeds to 40 phr. Attenuation results reveal that, the shielding efficiency increases with the increase of the filler concentration and are comparable to those of the conventional bismuth‐polymer shielding materials. Hence, the composites filled (BiO)2CO3 can be used for gamma ray shielding applications. The sample of 40 phr was subjected to gamma irradiation at doses from 30 up to 100 kGy. The dielectric and mechanical properties were investigated as a function of irradiation dose and filler concentrations. It was found that the irradiation dose up to 30 kGy causes an increase in the tensile strength and hardness. There is a remarkable decrease in dielectric constants at irradiation dose from 70 to 100 kGy. The dielectric constants decreased as the concentration of (BiO)2CO3 increased.