Tungsten carbide/carbon composite as novel functional filler in polypropylene enables highly efficient γ-ray shielding

Polymer-based composites attract increasing attention for γ-ray shielding because of their light weight, flexibility, and easy processing. In this study, tungsten carbide–carbon (WCC) with dual-scale characteristics, composed of ultrafine WC_1-x nanoparticles (3–4 nm) anchored on micrometer-scale carbon scaffolds, is incorporated into a polypropylene (PP) matrix to develop high-performance shielding materials. WCC possessing combined micro– and nano-scale features effectively mitigates nanoparticle agglomeration and enhances radiation attenuation across a wide energy range. Among the prepared composites, WCC45PP (45 wt % WCC) exhibits a linear attenuation coefficient (μ_L) of 3.597 cm^-1 and a radiation protection efficiency (RPE) of 48.3 % at 59.6 keV, while also showing superior mechanical and thermal stability compared with the composite containing commercial WC. These results indicate that WCC with dual-scale characteristics provides an effective strategy for designing lightweight, flexible, and lead-free polymer composites for γ-ray shielding applications.