Thermal responsive polyurethane/brominated isobutylene isoprene rubber co-continuous IPNs elastomer: From tunable shape memory behavior to high damping properties

Shape memory polymers may have the highest potential as materials for aerospace engineering because of their low density, adjustable stiffness, and controlled deformation; however, large shock effects are inevitable during the deformation process of space deployment structures. To overcome the impact of shock vibrations on such complex integrated structures, an innovative interpenetrating polymer network (IPN) preparation scheme through phase distribution adjustment is proposed. In this work, thermally responsive shape memory IPNs consisting of polycaprolactone-based polyurethane (PUPCL) and brominated isobutylene isoprene rubber (BIIR) were reported for the first time. The BIIR/PUPCL (5:5) IPNs exhibited high shape fixity and recovery rates (94.4 % and 89.6 %, respectively) and repeatable shape memory behavior. Furthermore, the IPNs presented a favorable loss factor (tan δ) of 0.60 and exhibited effective damping temperature range (tan δ > 0.3) covering 83.6 K (−43.4 °C to 40.2 °C), resulting in impressive damping properties. Finally, the working process of the hinge was simulated by constructing a layer-by-layer panel with smooth deployment 30 s after heating. In addition, a gripper-shaped module based on bending deformation was successfully fabricated, exhibiting particular energy-loss properties and acting as a shock absorber. This study provides a novel design for the preparation of multifunctional polymers with potential applications in hinges and booms for aerospace engineering and intelligent protective devices.