DURABILITY ASSESSMENT OF FABRIC-REINFORCED SHAPE-MEMORY POLYMER COMPOSITES

The present study is a baseline assessment of the environmental durability of current state-of-the-art, fabric-reinforced shape memory materials being considered for morphing applications. Tensile dog-bone-shaped specimens are cut along three different directions, namely, along 0 degrees, perpendicular (90), and at 45 degrees to the orientation of the fabric. The shape memory properties and elastomeric response before and after relevant environmental exposure to water at 49 degrees C for 4 days, in lube oil at room temperature and at 49 degrees C for 24 hours, and after exposure to Xenon Arc (63 degrees C, 18 minutes water and light! 102 minutes light only) and spectral intensity of 0.3 to 0.4 watts/m(2) for 125 cycles (250 hours exposure time) are measured. Weight loss of the as-received and conditioned specimens is monitored while the dog-bone-shaped specimens are subjected to recovery following fixation. Parameters being investigated include stored strain, recovery stress, shape fixity, shape recovery, and modulus in the glassy and rubbery state.