Synthesis and characterization of new polybenzimidazopyrrolones derived from pyridine‐bridged aromatic tetraamines and dianhydrides

A series of new polybenzimidazopyrrolones (polypyrrolone, PPy) were synthesized by polycondensation of pyridine‐bridged aromatic tetraamines, including 2,6‐bis (3′,4′‐diaminophenyl)‐4‐phenylpyridine and 2,6‐bis(3′,4′‐ diaminophenyl)‐4‐(3″‐trifluoromethyl)phenyl pyridine, with various aromatic dianhydrides. Experimental results indicated that the PPys, multiaromatic conjugated and semiladder polymers, showed good thermal stabilities with thermal‐decomposition temperatures of about 500 °C and residual weight retention at 750 °C as high as 84%. PPy films could be obtained by casting the precursor solution, poly(amide amino acid) on glass substrate, followed by thermal dehydrating at elevated temperatures. The polymer films exhibited excellent alkaline hydrolysis resistance, which retained their original shapes and toughness after boiling 7 days in 10% sodium hydroxide solution.