Flexible and lead-free polymer composites for X-ray shielding: comparison of polyvinyl chloride matrix filled with nanoparticles of tungsten oxides

Abstract

Polymer nanocomposites have been investigated as lightweight and suitable alternatives to lead-based clothing. The present study aims to fabricate flexible, lead-free, X-ray-shielding composites using a polyvinyl chloride (PVC) matrix and different nanostructures. Four different nanostructures containing impure tungsten oxide, tungsten oxide (WO₃), barium tungstate (BaWO₄), and bismuth tungstate (Bi₂WO₆) were synthesized through various methods. Subsequently, their morphological characteristics were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Also, energy-dispersive X-ray spectroscopy (EDS) analysis was performed to establish the presence of the filler in the PVC matrix. Two different weight ratios of these nanostructures (20% wt and 50% wt) were used to produce the PVC composites. To investigate attenuation parameters, the prepared composites were irradiated with X-rays at tube voltages of 40, 80, and 120 kV. The results showed that the PVC composites containing 20% wt Bi₂WO₆ had the highest linear attenuation coefficient (µ) at all three voltages. Furthermore, they had the lowest half-value layer (HVL), tenth-value layer (TVL), and 0.5 mm equivalent lead thickness values at each of the three voltages. The PVC composites containing 50% wt Bi₂WO₆ had attenuation coefficients greater than those reported for PbO at all three X-ray voltages. Among the studied tungsten nanostructures, bismuth tungstate had the best attenuation performance for X-ray protection. Additionally, this composite is light, flexible, and non-toxic, making it a promising alternative to lead aprons.

Keywords: Linear attenuation coefficient; Polyvinyl chloride; Tungstate nanostructure; X-ray.