Interpenetrating shape memory polyimide-polyaniline composites with electrical conductivity

Shape memory polyimides (SMPI) with adjustable shape recovery temperatures have been paid much attention in both fundamental research and practical applications. However, the intrinsically electrical insulation of SMPIs limits their applications. In this article, the electrically conductive shape memory polyimide-polyaniline (SMPI-PANI) composite with interpenetrating networks was synthesized by in situ polycondensation. Compared with pure SMPI, the electrical resistivity of SMPI-PANI composites reduced by about 12 orders of magnitude when the PANI content was 15 wt%. The addition of PANI had less influence on the glass transition temperature and storage modulus in glassy state. But the storage modulus of SMPI-PANI composites in rubbery state was over 40 times higher than that of pure SMPI, indicating that SMPI-PANI composites have higher stiffness during shape recovery. The SMPI-PANI composites demonstrate excellent shape memory performance with shape fixation ratio higher than 97% and shape recovery ratio higher than 93%. The SMPI-PANI composites also have good thermal stability with the effective decomposition temperatures higher than 150?. The SMPI-PANI composite in our work is a potential material for deployable aerospace structure.