▎ 摘　　要

Efficient stabilization strategies for polymeric materials are critical to guarantee them to withstand decades of service in multiple aggressive environments. Graphene oxide (GO) has been identified as a kind of promising antioxidant to improve the oxidative stability of polymers; however, a comprehensive understanding of the multifunctional stabilization mechanisms of GO for polymeric materials subjected to various weathering factors is still missing. Here, we explored the effect of the thermally reduced GO (TrGO) on the thermo- and photo-oxidation of isotactic polypropylene (iPP), respectively. The addition of TrGO could simultaneously suppress the thermo- and photo-oxidation of iPP, and the stabilization effects became stronger with increasing TrGO content. While similar carbonyl species were formed under both thermo-oxidation and photo-oxidation of iPP, the proportion of ketone was much higher under thermal-oxidation. The incorporation of TrGO did not change the proportion of the degradation products under thermo-oxidation; however, the proportion of lactone was risen under photo-oxidation, suggesting a different degradation mechanism. Versatile stabilization mechanisms of TrGO were further revealed by UV-Vis spectroscopy and oxygen permeability tests, which were related to the extraordinary ability of TrGO in the block of UV light (deter), suppression of oxygen diffusion (delay), and scavenging of free radicals (defend). In this contribution, we clearly demonstrated different multifunctional and synergistic stabilization functions of TrGO for thermo- and photo-oxidation respectively, which shall be useful for the practical design of next-generation GO-based stabilizers with superior efficiency.