Synthesis and Characterization of Poly(ether ether ketone-co-benzimidazole)s Based on 2-(2'-Hydroxyphenyl) benzimidazole

A series of novel poly(ether ether ketone)s containing benzimidazole groups with precise structures in high yields were synthesized from various stoichiometric ratio mixtures of m-dihydroxybenzene, 2-(2'- hydroxyphenyl)benzimidazole and 4,4-difluorodiphenylmethanone via a C-N/C-O coupling reaction process using sulfolane as a solvent. The reaction was carried out at 210 degrees C in the presence of anhydrous potassium carbonate. The structures of the resulted polymers were characterized by means of FTIR, H-1 NMR spectroscopy, elemental analysis, and the results were largely consistent with the proposed structure. XRD studies indicated that the resulted polymers are non-crystalline. The polymers have good solubilities in common organic solvents. The polymers showed high glass transition temperatures (T-g = 125-237 degrees C) and high thermal stability (T-d5% = 497-539 degrees C in nitrogen, 466-548 degrees C in air). At the same time, as the benzimidazole unit content in the copolymer increased, the thermal properties of the prepared polymers improved. Moreover, the resulted polymers showed good fluorescence properties and the fluorescence emission peak was 465 nm.