Synthesis and characterization of phenylated pyrazino-benzimidazophenanthroline polymers

Novel phenylated quinoxaline tetraamines have been prepared and polymerized with 1,4,5,8-naphthalenetetracarboxylic acid in polyphosphoric acid solution. The resulting BBB-type polymers with pendant phenyl groups along the polymer backbone are soluble in m-cresol. The polymers, with inherent viscosities ranging from 0.3 to 0.6 dl/g in sulfuric acid, exhibited thermal stabilities near 500°C under nitrogen and near 400°C in air.