The Italian-FOAM experiment evaluates the recovery of shape memory epoxy foam in microgravity, which was obtained on ground consisting of various geometric complexities. Working shape memory polymers (SMPs) are based on the ability of these materials to fix a given deformation by cooling below a certain transition temperature (which is mostly the glass transition temperature). Upon reheating to above the transition temperature, the polymer chains reorganize, resulting in a macroscopic recovery of the original shape. Foaming is another way to tailor SMP properties for application requirements; foams generally have reduced mechanical stiffness and strength but enhanced compressibility. I-Foam developed a new foaming technology which is able to produce thermoset foams starting from thermosetting powders.
This method is simpler than conventional foaming methods and gives homogeneous closed-cell foams with excellent mechanical properties. It was observed that foams produced by solid-state foaming present remarkable shape memory properties. In fact, these foams, which are very rigid at room temperature, become spongy when heated above the Tg (glass transition temperature); in this state they can be packed up to the complete collapse of the pores, without generating any foam damage. Cooling below transition temperature, this compact structure remains stable with no constraining force. When heated above the transition temperature, the foam recovers its original shape.
In order to study the behavior of this new class of materials in microgravity, I-Foam includes a set of experiments to test: the shape recovery of an epoxy block, the unfolding of a complex structure, and a simplified actuator. On-ground analysis of the retrieved samples will be performed in the PI’s lab and compared to samples tested in the same conditions on ground in order to investigate the behavior of this new class of materials in a microgravity