Synergistic Enhancement of Mechanical, Adhesive, Thermal and Ablation Performance of Pdms Based on Double Bond Epoxidation Modification

Abstract

As a typical flexible thermal protection material, the application of pure polydimethylsiloxane (PDMS) is greatly limited by its poor adhesion, insufficient mechanical properties and anti-ablation performance. This study proposes an efficient strategy of bulk modification to prepare epoxy-modified liquid silicone rubber (ECVS@PDMS) by in-situ double bond epoxidation, which retained the main chain structure of polysiloxane and achieved good compatibility with PDMS. The modified ECVS@PDMS simultaneously addresses the aforementioned limitations of PDMS, with the tensile strength and adhesion strength increased by 697% and 260%, respectively, compared to pure PDMS. Besides, the initial decomposition temperature increases by 44.8℃ and the residual carbon at 800℃ increases by 19.6%. More importantly, the anti-ablation performance is greatly enhanced, as ECVS promotes the formation of well-structured SiC ceramic crystals during ablation, effectively resisting the thermal erosion. This bulk modification method provides a novel design approach for the preparation of PDMS-based flexible ablation resistant coating with outstanding overall performance.

Keywords: ablation properties, adhesive properties, epoxidation