Rapid-actuating high-Tg shape memory polyimide composites with synergistic “micro-nano” thermal conduction networks

Shape memory polyimide (SMPI) is one of the most promising intelligent materials and has a high potential for deformable flexible electrodes, intelligent thermal management devices, and high temperature active deployable structures, etc. In this paper, silane-modified AlN nanoparticles (M-AlN) are composited with SMPI matrix resin to prepare fast-response high-Tg shape memory composites. Besides, nano-sized AlN and micron-sized Al2O3 are used to construct “micro-nano” synergistic thermal conduction networks, in which the AlN acted as the “thermal conduction island”, and the Al2O3 acted as the “thermal conduction bridge”. The results show that the in-plane thermal conductivity of Al2O3/M-AlN/M-SMPI-2 is 5.99 W m−1K−1, compared with SMPI, its thermal conductivity increases by 91%. In addition, the shape transition temperature of Al2O3/M-AlN/M-SMPI-2 was higher than that of pure SMPI, which was at 426 °C, and the thermal response shape recovery speed is also greatly improved by 433%, which can be used in rapid-actuating and high temperature active deformation structure.