Structural and shielding properties of P(VDF-HFP)-Bi2O3 multilayered polymer composites

Flexible, lead-free Bi₂O₃/poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] composite films were developed as sustainable X-ray shielding materials for medical and industrial applications. Films with Bi₂O₃ loadings of 5–50 wt% were fabricated via solution casting and characterized using SEM, AFM, XRD, FTIR, and TGA to assess surface morphology, crystallinity, thermal stability, and radiation attenuation. Mechanical testing and X-ray attenuation measurements at 60 and 80 kVp revealed a clear trade-off between shielding efficiency and mechanical flexibility. Among all compositions, 20 wt% Bi₂O₃offered the most balanced performance, with a tensile strength of 10.7 ± 0.1 MPa, elongation at break of 4.7 ± 0.9 %, crystallinity of 81.99 %, hydrophobicity (water contact angle) of 120.46 ± 0.64°, 88.0 ± 0.1 % attenuation at 60 kVp (four-sheet configuration), and an enhanced maximum degradation temperature (T_max) of 480.13 °C. Higher filler loadings improved attenuation up to 92.0 ± 0.2 % but substantially reduced flexibility, while lower loadings preserved mechanical properties but compromised shielding. These results demonstrate that optimized Bi₂O₃/P(VDF-HFP) composites can deliver lightweight, flexible, and environmentally friendly alternatives to lead-based shielding, with tunable performance for specific application needs.