Novel high Tg, organosoluble poly(ether imide)s containing 4,5-diazafluorene unit: Synthesis and characterization

The synthesis of aromatic poly(ether imide)s containing 4,5-diazafluorene units in the polymer backbone is described. 9,9-di [4-(4-Aminophenoxy)phenylene]-4,5-diazafluorene (3), which was used as a new monomer, was synthesized with 4,5-diazafluoren-9-one as the starting material. This diamine monomer was employed in reactions with a variety of aromatic dianhydrides to furnish poly(ether imide)s. These 4,5-diazafluorene- based polymers showed solubility in polar amidic solvents such as NMP, DMAc and DMF, good optical transparency, and high thermal stability. The glass transition temperatures (T-g) of these poly(ether imide)s were recorded between 325 and 356 degrees C with the help of differential scanning calorimetry (DSC), and the T-g determined by dynamic mechanical thermal analyses (DMA) stayed in the range of 329-363 degrees C, and the 10% weight-loss temperatures all occurred above 560 degrees C in both nitrogen and air atmospheres. In addition, the flexible polyimide films possessed tensile strengths in the range of 64-101 MPa, tensile modulus of 1.8-2.1 GPa, and elongations at break of 6-13%. (C) 2014 Elsevier Ltd. All rights reserved.