Synergistic strategy of green-processed CeO2 and crosslinking network design for simultaneous improvement in mechanical properties and thermal stability of silicone rubber

Silicone rubber suffers from low mechanical strength and thermal stability, while conventional reinforcement often exacerbates the strength–toughness trade-off. Here, we present a strategy to construct high-performance silicone rubber composites via synergistic regulation of crosslinking networks and interfacial interactions. A multifunctional crosslinker PTMS, was synthesized to enrich reactive site density and strengthen the network. CeO 2 particles were eco-efficiently functionalized by silanization, ensuring homogeneous dispersion and interfacial compatibility with rubber matrix. Importantly, CeO 2 lowers effective crosslink density, compensating extensibility loss typically induced by rigid nanofillers, while its reinforcing effect enables simultaneous strength and toughness enhancement. The composites deliver a tensile strength of 1.44 ± 0.08 MPa (180% increase), toughness of 1.95 ± 0.05 MJ m −3 (187.5% improvement), elongation at break of 225.04% ± 16.10%, and fracture energy of 1.57 ± 0.12 kJ m −2 . Beyond reinforcement, CeO 2 acts as a radical scavenger and thermal stabilizer, raising onset decomposition temperature from (424.8 °C), maximum decomposition temperature (560.3 °C), and limiting oxygen index (28.40 ± 0.20%). This work provides a method for overcoming long-standing trade-offs in silicone rubber and highlights the multifunctional role of nanofillers in simultaneously optimizing mechanical robustness, extensibility, thermal stability, and flame retardancy.