Synthetic study of aromatic polybenzoxazinone derived from methylene-4,4′-diaminodiphenyl-3,3′-dicarboxylic acid

Polybenzoxazinones were prepared in two successive steps from methylene-4,4′-diaminodiphenyl-3,3′-dicarboxylic acid and azodicarbonyl chloride in 40–60% yield. These polymers were characterized by molecular weight and IR and NMR spectra. Their physical properties like solubility, viscosity, and thermal stability were also studied in detail.