Effects of Compatibilizers on the Rheological, Thermal, Mechanical, and γ-Ray Shielding Properties of WO₃/PP Composites

Polymer-based composites are receiving more and more attention in the field of radiation shielding due to their good recyclability and processability; however, the poor compatibility between the organic polymer matrices and inorganic fillers usually appears as a bottleneck to their full shielding effectiveness. Although compatibilizers are widely utilized to suppress the agglomeration of inorganic fillers, their impact on the overall performance of composites is less concerning. In this study, we systematically investigate the effects of three common compatibilizers, i.e. 3-aminopropyltriethoxysilane (KH550), 3-methacryloxypropyltrimethoxysilane (AM), and maleic anhydride–grafted polypropylene (PP-g-MAH), on the properties of WO₃/PP composites, including rheological performance, thermal properties, crystallization behaviors, mechanical properties, and radiation shielding effectiveness. It was found that in addition to dispersing WO₃ particles, KH550 and AM contribute to the formation of a heterogeneous network structure in the PP matrix, and especially for KH550, it can effectively promote the structural stability, thermal stability, crystallinity, and toughness of WO₃/PP composites. More importantly, WO₃/PP-S-K exhibits the best shielding performance, with linear attenuation coefficients of 3.71 cm⁻¹ and 0.279 cm⁻¹ under ²⁴¹Am (59.6 keV) and ⁶⁰Co (1332 keV) irradiation, respectively. Compared with the pristine WO₃/PP composite, the half-value layer is markedly reduced to 0.187 cm and 2.48 cm, representing decreases of 25.5% and 60.6%. These findings underscore the enhancements in shielding performance and structural integrity achieved through modification with KH550, thereby providing valuable insights for the future development of environmentally friendly radiation shielding materials.