Synthesis and characterization of poly(N-arylenebenzimidazole ketone ketone)s

Poly( N -arylenebenzimidazole ketone ketone)s (PNABIKKs) consisting of m - and p -phenylene linkages have been synthesized by nucleophilic aromatic substitution from bis(benzimidazolyl) derivatives containing sulfonyl, carbonyl, and ether groups with activated aromatic difluorides in sulfolane at 210 °C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier tramsfom infrared (FTIR), proton nuclear magnetic resonance ( 1 H NMR) spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements demonstrated that polymers had high glass transition temperatures ( T g >220 °C) and good thermal stability with high decomposition temperatures ( T D >480 °C). These novel polymers also showed good solubility.