Polybenzimidazoles (PBIs) derived from non-coplanar dibenzoic acid containing imidazole (IDBA): Synthesis, characterization and properties

Abstract

A novel non-coplanar imidazole dibenzoic acid (IDBA) was successfully prepared, and its structure was carefully characterized by FT-IR, NMR, MS and elemental analysis. Polybenzimidazoles (PBIs) derived from IDBA were synthesized by a conventional one-step method in polyphosphoric acid (PPA). The obtained PBIs exhibited good organic solubility, excellent thermostability and interesting optical properties. The initiation decomposition temperature for these PBIs ranged from 560-600 °C, and the 5% weight loss temperature (T5) for all these PBIs was above 600 °C in N2. No obvious glass transition for these PBIs was observed below 350 °C. These PBIs shows UV-vis absorption maximum around 360-380nm and strong photoluminescence emission (blue light) around 430-440nm in solution, which is red-shifted to 490-510nm in the solid state. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.