Polyimide thin films with high thermal stability and resistance will contribute to the development of flexible energy devices, which could be compatible with their high temperature fabrication process. Thus, we have prepared poly(amic acid) solutions with bisbenzimidazole and bisbenzoxazole based diamines and finally fabricated polyimide thin films. After comparing with commercial type polyimides, the polyimides containing bisbenzimidazole and bisbenzoxazole segments showed excellent thermal decomposition temperatures (of 581 and 584 °C, respectively), outstanding mechanical properties (with a tensile strength of 218 and 192 MPa, respectively), and relatively low water absorption percentages (of 0.68% and 0.63%, respectively). The superior properties should be ascribed to the rigid molecular chain skeleton, strong inter- and intra-molecular-chain forces, and hydrogen bonds.
