Decoupling physical mass transfer and chemical quenching: extreme aging mechanism of fluororubber reinforced by surface-fluorinated confined cerium dioxide.

A mesoporous silica composite (F-CeO2@SiO2) with perfluorination and pore-confined CeO2 tackles fluororubber (FKM) thermal-oxidative degradation. Perfluoro-interface enables nanodispersion and entanglement, reaching 13.10 MPa tensile strength. At 250 °C, confined CeO2 quenches radicals, retaining 8.93 MPa. At 300 °C, pure SiO2 barrier fails, but confined CeO2 sustains quenching, keeping elongation at 165.8% and avoiding embrittlement. This distinguishes physical heat transfer from chemical anti-aging.