Lightweight fluorinated block copolyimide aerogels for high-temperature shape memory

Abstract

Shape memory polyimide aerogels represent a promising class of next-generation materials for aerospace applications, owing to their intrinsic low density, unique thermo-induced shape memory behavior, and exceptional resistance to extreme environmental conditions. However, aromatic polyimides exhibit poor shape memory performance due to high chain rigidity and strong π-π stacking interactions, while increasing the flexibility of the molecular chains can disrupt the formability of the three-dimensional structure of aerogels. In this study, we successfully synthesized a series of block copolyimide aerogels by systematically manipulating the molecular structure. Through controlling the polymerization degree of soft segments, block copolyimide aerogels demonstrated thermo-induced shape memory behavior at temperatures of approximately 320 °C, with both shape recovery and fixation rates exceeding 97 %. Notably, these block copolyimide aerogels exhibit good formability and lightweight with a low density below 0.19 g cm⁻³. Furthermore, after more than ten shape memory cycles, the recovery and fixation rates remain consistently above 95 %, indicating excellent long-term stability. This study offers new insights into the development of lightweight and high-temperature shape memory materials, with significant potential for future aerospace applications.