Synthesis and Characterization of New Organosoluble and Thermally Stable Polyimides Containing Pyridine and Anthracene Units

Summary A series of new polyimides were obtained by the polycondensation reactions of the three diamines containing pyridine and anthracene units with various aromatic tetra carboxylic dianhydrides via both two‐step and one‐step methods. The precursors and monomers were characterized by elemental analysis, FT‐IR, 1 H‐NMR and 13 C‐NMR techniques. The structure of the polyimides was confirmed by FT‐IR, and 1 H‐NMR spectroscopy, inherent viscosity and molecular weight measurements. All the polyimides are soluble in aprotic solvents such as NMP, DMF, DMAc and DMSO. These polyimides exhibit T g in the range of 213–317 °C and 10% weight loss (T 10 ) takes place in the range of 414‐531 °C in N 2 401–521 °C in air and the char yield varies between 38–54%. The polymer films have tensile strength in the range of 84–110 MPa, elongation at break in the range of 11.2–13.8% and tensile modulus in the range of 1.1–1.4 GPa and low moisture absorption (0.87–1.16). All of these new polymers show excellent thermal stability and the polyimide films have good mechanical properties.