Atomic oxygen resistant phosphorus-containing polyimides for LEO environment

In this study, a series of polyimides had been prepared from bis-(4-aminophenoxyl) phenoxyl phosphine oxide (p-DAPO4) with corresponding dianhydrides via two-stage polycondensation method. The inherent viscosities of the polyamide acid were in range of 0.43–0.92 dL/g, and atomic oxygen (AO) exposure experiment was conducted in a ground-based atomic oxygen effects simulation facility with the filament charge and bound of magnetic field to determine the AO erosion-resistant properties of the polyimide films. Field emission scanning electron microscopy (FE-SEM), attenuated total-reflection Fourier transform infrared spectrometer and X-ray photoelectron spectrometer were employed to characterize the change on the surface of films after AO exposure, and the mass loss of some phosphorus-containing polyimide films reduced to about 20% that of Kapton® HN film as AO fluence of 4.14 × 1020 atoms/cm2. The morphologies of heave residues of the polyimide films acting as a barrier to further erosion could be obtained from FE-SEM. The results indicated that a phosphate-type layer was left on the surface of phosphorus-containing polyimide films after AO exposure.