Mechanical and thermal stability properties improvement of polyethylene wax-coated tungsten carbide/high-density polyethylene γ-rays shielding composites through irradiation-induced crosslinking

It is well known that the properties of polyethylene can be improved by irradiation-induced crosslinking the formation of three-dimensional network structures. This paper investigated the effects of gamma irradiation on the mechanical, thermal stability, and γ-rays shielding properties of TAIC-containing γ-rays shielding composites (HDPE/WC-PEW/TAIC). As a result, SEM images showed that agglomerations are alleviated after polyethylene wax (PEW) coated tungsten carbide (WC). The tensile strength and hardness increased from 25.39 MPa to 94 HA to 29.49 MPa and 98 HA after 50 kGy irradiation in vacuum as compared with all composites, while the thermal stability was also improved. The XPS and gel content results showed that the more crosslinked structures generated after 50 kGy irradiated in vacuum between high-density polyethylene (HDPE) and PEW, but irradiation in air is accompanied by the destruction of polymer skeleton. Moreover, the shielding rates of HDPE/WC-PEW/TAIC with thickness of 2 mm and containing 50 wt% WC can exceed 50% and 25% for 137 Cs and 60 Co sources respectively. In summary, HDPE/WC-PEW/TAIC could be an alternative to lead as γ-rays shielding material with excellent mechanical, thermal, and γ-rays shielding properties after 50 kGy irradiation in vacuum.