Thermal Protection Performance of Porous Carbon Ablators with Three Different Matrices

Abstract

A porous carbon material with a three-dimensional network and open-cell structure was applied to preform new lightweight ablators. The materials impregnated into the porous carbon were polyimide, phenol, and poly(methyl methacrylate). To evaluate the performance of the ablators, their thermal response and recession resistance were evaluated using an arc wind tunnel. All the ablators exhibited thermal insulation due to the pyrolysis reaction, and they decreased in the surface temperature due to gas blocking. Poly(methyl methacrylate) was especially found to be the most effective for the thermal responses desired here. Furthermore, the ablators showed stable recession resistance, which was comparable to that of existing lightweight ablators. This was attributed to the fact that the porous carbon preform had high resistance to mechanical erosion, which in turn maximized the effect of blownoff pyrolysis gas in improving recession resistance. Among the materials, the poly(methyl methacrylate) porous carbon ablator achieved the best recession resistance at low heat flux; this was the highest recession resistance measured thus far for a lightweight ablator.