Atomic oxygen-induced polymer degradation phenomena in simulated LEO space environments: How do polymers react in a complicated space environment?

Effect of relative intensity of atomic oxygen and vacuum ultraviolet (UV) in the synergistic effect of polyimide erosion was investigated. The relative intensity of atomic oxygen and UV was adjusted by rotating the polyimide sample at the crossover point of the beam axes of atomic oxygen and UV which crossed 90∘90∘. The erosion rate of polyimide was measured by a quartz crystal microbalance. It was confirmed that the UV exposure at the atomic oxygen-exposed polyimide promoted the desorption of carbon oxides from the surface. In contrast, no mass change was detected when UV irradiated the polyimide surface without simultaneous atomic oxygen exposure. By changing the relative intensity of atomic oxygen and UV, increase in erosion rate up to 400% was observed when relative UV intensity is high.