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 500degreesC and residual weight retention at 750degreesC 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. (C) 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1845-1856, 2004.