Experimental Study on Polyimide Foam for Satellite

BSPIF-S-7.5A, a kind of open cell and low-density polyimide foam was developed for Chinese satellite. The polyimide foam is thermal isolation material with low thermal conductivity and high glass transition temperature. Basic physical properties, thermal physical properties, mechanical properties have been studied. For validating space environment resistance of polyimide foam, outgassing in vacuum, thermal cycle, total dose radiation, thermal vacuum and atomic oxygen tests have been performed. The apparent core density of this foam is as low as 7.5 ± 0.5 kg m⁻³. Its volume percentage of open cells is over 98%, which is beneficial to outgas in orbit. Coefficient of thermal expansion is less than 40 × 10^–6 K⁻¹ in the temperature range from − 170 to 135 ℃. Thermal conductivity in vacuum increases from 2.7 to 42.3 mW (m K)⁻¹ with temperature rising from – 130 to 135 ℃. After severe space environment tests, thermal conductivity becomes even lower, compressive strength raises slightly, but shear property declines apparently. Covered with polyimide film, polyimide foam can resist atomic oxygen erosion effectively. Therefore, the polyimide foam is superior thermal insulation material for space application, which is ideal for satellite structure.