polyphosphazenes for heat shielding

What is it about?

The ablative properties of elastomeric insulations are often inadequate for solid rocket motor (SRM) applications. These materials exhibit relatively high erosion rates during the operation of an SRM unless the charred insulation layers are reinforced with suitable fibre fillers. As alternatives to traditional synthetic rubber materials, flexible semi-inorganic rubbers such as polyphosphazene elastomers are now used as state-of-the-art heat-shielding materials. We have successfully managed to prepare a poly(diaryloxyphosphazene) elastomer (PDPP) as well as some insulation materials that are free of any fibrous fillers (with only the addition of inorganic oxides, such as fumed silica and zinc oxide). These polyphosphazene insulations exhibit excellent linear ablation rates as compared to synthetic organic rubbers. In addition, integrated and rigid charred layers without noticeable swells are formed on the surfaces of the matrices resulting in ‘coral fleece-like’ hollow microtubes, which show better ablative resistance performance than do traditional insulations.

Featured Image