Effects of atomic oxygen on epoxy-based shape memory polymer in low earth orbit

Atomic oxygen is a dominant component of the low earth orbit and can erode most spacecraft polymeric material. In this article, the atomic oxygen erosion resistance tests of an epoxy-based shape memory polymer are carried out in a ground-based atomic oxygen simulator with a vacuum space chamber. The samples, before and after the atomic oxygen exposure, are compared in appearance, surface morphology, mass, main component, dynamical and static mechanical properties, and shape memory properties. The atomic oxygen exposure causes oxidization reaction of the material, which leads to surface roughen and mass loss, while the shape memory polymer main components remain same. The results of dynamical and static mechanical tests indicate that the atomic oxygen exposure has little effect on the storage modulus and glassy transition temperature (Tg), whereas the elongation, elastic modulus, tensile strength, and yield strength decrease since the atomic oxygen exposure gives rise to tiny cracks. The shape memory property has rarely changed since the atomic oxygen erosion is mainly located near the surface of the sample.