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

Abstract 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.