Enhanced flexibility and ablative performance of silicone rubber by constructing an interpenetrating zirconium-containing polysiloxane double network

To achieve uniform distribution of heteroatoms in silicone rubber, further simultaneously improving the flexi-bility and ablation resistance, polydimethylsiloxane with an interpenetrating zirconium-containing double-network (Zr-PDMS) was prepared. Compared to pure PDMS, the tensile strength and elongation-at-break of Zr-PDMS with interpenetrating double-network were increased by 615.33% and 124.23%, respectively, exhibiting significantly enhanced flexibility. Ablation analysis indicated that Zr-PDMS showed excellent anti-ablation performance, exhibiting obviously decreased mass ablation rate and charring rate. Most importantly, different from the crisp charred layers of pure PDMS as well as ZrO2 blends, Zr-PDMS formed stable and coherent charred layers after ablation tests. The improvement correlated to the in-situ formation of tetragonal ZrO2 in the char layer of Zr-PDMS, which could avoid the generation of defects in the ZrO2 blends char layer were discussed in detail. This work provided a new strategy of high flexible silicon rubber with excellent ablative performance, which can be expected to be well applied in the hypersonic spacecrafts.