Mechanical and gamma radiation shielding properties of natural rubber composites: effects of bismuth oxide (Bi2O3) and lead oxide (PbO).

This work aims to compare the performance between natural rubber (NR) composites with lead oxide (PbO) and bismuth oxide (Bi2O3) as shielding fillers for gamma radiation shielding applications. Modulus at 100% elongation, tensile strength, elongation at break, hardness and a specific gravity of the NR composites were investigated. The results indicated that NR/Bi2O3 and NR/PbO composites have no significant difference in terms of modulus and hardness values, while the NR/PbO composite exhibited better tensile strength and specific gravity than that of NR/Bi2O3 composite. However, NR/Bi2O3 composite exhibited better performance in oil resistance and thermal stability than the one with PbO. Gamma radiation shielding properties including mass attenuation coefficient ( μ m ), effective atomic number (Zeff), effective electron density (Ne) and half-value layer (HVL) have also been studied. It is seen that both the composites exhibited better radiation shielding properties. Furthermore, the radiation properties were in good agreement with the calculated theoretical values. In addition, both the composites of NR with PbO and Bi2O3 particles showed excellent radiation shielding properties compared to neat NR as well as commercially available materials including window, ordinary concrete and haematite-serpentine. The material developed in the present investigation can be used as efficient flexible radiation shielding materials. However, lead (Pb) is not suitable to use as a radiation shielding material due to its toxic nature to the human and the environment. Therefore, NR with Bi2O3 is an appropriate choice for producing novel wearable radiation shielding materials to manufacture gloves, aprons, rubber underwear and other wearable materials. [ABSTRACT FROM AUTHOR]