Manufacturing of shape memory foams in hypergravity and simulated microgravity

Abstract. Shape memory polymer (SMP) foams have the potential to be used in space application for self-deployable structures and actuators. For this reason, shape recovery tests have been performed in microgravity, but these foams have been never manufactured in space, because of experimentation costs and flight opportunities. Some foams have been manufactured on-Earth in a random positioning machine (RPM) and a large diameter centrifuge (LDC) under different conditions with the aim of understating if the gravity can play a role during foaming. Foams have been characterized by 3D micro-Computed Tomography (micro-CT) and the effect of the foaming condition on the foam structure is discussed in this study. For the first time, it has been observed that SMP epoxy foams produced by solid state foaming present open porosity with a negligible contribution of closed pores. Moreover, it is confirmed that SSF foams is minimally affected by the gravity conditions apart the contribution of the gravity vector on the heat transfer conditions during foaming.