Nano-BaSO4/waste PVC/natural rubber composites as lead-free and sustainable diagnostic X-ray shielding materials: Fabrication and performance evaluation

Sustainable X-ray shielding composites based on natural rubber (NR), nano-barium sulfate (nano-BaSO 4 ), and waste poly(vinyl chloride) (w-PVC) were successfully developed for diagnostic X-ray protection applications. Prior to fabrication, the X-ray shielding properties of the composites were theoretically predicted using XCOM to determine the optimum nano-BaSO 4 content required to achieve Pb eq exceeding the minimum requirement of 0.35 mmPb. The fabricated composites with the optimum nano-BaSO 4 content of 500 phr were subsequently characterized for cure characteristics, thermal stability, physicochemical, mechanical, and X-ray shielding properties at tube voltages of 60, 100, and 150 kVp. The results showed that the addition of nano-BaSO 4 enhanced the shielding properties, with the μ value increasing from 0.50 cm −1 for NR to 10.50 cm −1 for nano-BaSO 4 /NR composites at 100 kVp. Additionally, the composites containing w-PVC and nano-BaSO 4 exhibited Pb eq values of 0.34 – 0.39 mmPb at 100 and 150 kVp, indicating their suitability for diagnostic X-ray shielding applications. The addition of w-PVC also improved processability by reducing Mooney viscosity and enhancing thermal stability. Although the addition of both fillers reduced tensile strength and elongation at break, the composites still maintained sufficient flexibility and structural integrity for shielding applications.