Eco-friendly flexible polyvinyl-chloride composites reinforced with brine sludge and WO 3 : structural, thermal, and radiation shielding performance

Abstract This study investigated the structural, thermal, and gamma-ray shielding performance of flexible polyvinyl chloride (PVC) composites fabricated and reinforced with tungsten oxide (WO 3 ) and brine sludge (BS). The composites were prepared with varying WO 3 content (10–30 wt%) and a constant 10 wt% BS content. The composites were fabricated using two-roll milling and hot-pressing techniques under controlled conditions. Structural and morphological characterization was carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), while thermal stability was evaluated by thermogravimetric analysis (TGA). The shielding properties of the developed PVC-composites were evaluated using a high-purity germanium (HPGe) detector with Am-241, Cs-137, and Co-60 gamma-ray sources. The experimental attenuation coefficients of the developed composites were compared with theoretical calculations using X-COM program, and the relative deviation not exceed 6 %. The radiation attenuation performance was evaluated based on the equivalent thickness required to match 2 mm of lead at gamma-ray energies. The pure PVC sample exhibited the lowest radiation shielding efficiency, RSE (52 % at 0.0595 MeV and a thickness of 2 cm), while PVC-BW 3 demonstrated the best shielding performance (98 % at 0.0595 MeV and a thickness of 2 cm). These results suggest that the prepared PVC composites can be used in X-ray and gamma radiation shielding applications, particularly for low and medium energy levels, as they are flexible, lightweight, and environmentally friendly polymer materials.