Tough silicone elastomers with recycling stability enabled by dynamically arrested bicontinuous phases

Achieving silicone elastomers that combine high toughness with recycling stability remains a persistent challenge, as conventional toughening strategies enhance energy dissipation at the expense of reversible network reconfiguration for stable reprocessing. Here, we address this challenge by engineering a dynamically arrested bicontinuous phase within a silicone elastomer. Grafting long perfluoroalkyl chains onto a polysiloxane backbone induces phase separation, forming a continuous fluorinated phase for efficient energy dissipation alongside a complementary silicone phase that preserves elasticity. The architecture is arrested by a dual dynamic network of β-amino ester covalent bonds and hydrogen-bonding segments, which suppress phase coarsening while enabling thermal reprocessing without degrading intrinsic phase structure. The resulting elastomer achieves an exceptional toughness of 29.3 MJ m⁻³ and an elongation of 1510%, while exhibiting outstanding recycling stability, with properties well retained after five reprocessing cycles. By simultaneously resolving the conflicting demands of toughness and recycling stability, this work establishes a viable pathway toward recyclable, high-performance silicone rubber materials with industrial relevance.