Multiscale Evaluation of Thermo‐Oxidative Aging Susceptibility of Polyethylene Modified With Antioxidant Functionalized Nano‐ <scp> TiO ₂ </scp> Particles

ABSTRACT The corresponding relation between the thermo‐oxidative aging level and the multiscale assessment of the properties for polyethylene is a challenging issue. A novel hybrid antioxidant, designated TiO 2 ‐KH550‐PA, was synthesized, and the influence of the filler on the thermal‐oxidative aging behavior of polyethylene was investigated from multiple scales. The results show that the TiO 2 ‐KH550‐PA can provide a better synergistic protective effect for the thermo‐oxidative aging resistance of polyethylene. Compared with pure polyethylene, the polyethylene containing TiO 2 ‐KH550‐PA has excellent anti‐aging performance, including a decrease by 86.48% in the diffusion coefficient of O 2 molecule at 373 K, a decrease by 16.25% in the maximum displacement of O 2 molecule, and a decrease by 14.78% in the free volume fraction. The accelerated aging tests show that the TiO 2 ‐KH550‐PA filler can suppress the generation of chromogenic groups and inhibit the transfer reaction of free radicals, thus strengthening the thermo‐oxidative aging resistance of polyethylene.