Increasing Flexibility of Polymers in the Application of Complex Space Craft Heat Shield Geometries

Highly crosslinked polymers, commonly utilized in spacecraft component fabrication, especially for heatshields, have historically encountered challenges due to their inherent brittleness. To overcome this issue, researchers have explored the incorporation of additives into the polymer backbone to enhance flexibility and durability. This study aims to improve the flexibility and durability of highly crosslinked polymers by introducing long-chain aliphatic silicon-based additives with varying molecular weights into the polymer backbone. By increasing the flexibility of these brittle polymers, they can be effectively employed in constructing intricate curvatures for heatshields, eliminating the need for gap fillers. In this study, we investigated six different additives, comparing them to a highly crosslinked high-temperature polymer used as a baseline. Various characterization techniques, including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dilatometry, dynamic mechanical analysis (DMA), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR), were employed to assess the properties of the materials. The FTIR and NMR results indicated the successful incorporation of the silicon-based additives into the polymer backbone. Furthermore, thermal characterization results demonstrated that certain additives exhibited superior flexibility and lower densities compared to the baseline polymer.