Synthesis, Characterization and Properties of Polymeric p-Benzoyl-4,4'-Diaminobenzoylaniline

An aromatic polyamide was synthesized by low-temperature poly-condensation reaction from terephthaloyl chloride and 4,4'-diaminobenzanilide (4,4'-DABA). The synthesized polyamide had a characteristic peak of carbon atoms in the amide group at 166 ppm, which was demonstrated by the solid nuclear magnetic resonance carbon spectrum. It was shown to be the stretching vibration absorption peak of the amide N-H bond at 3342 cm⁻¹ by Fourier infrared (FT-IR) spectroscopy. It was obtained that the energy band near 1100 - 1276 cm⁻¹ belongs to the absorption peak of the para-substituted benzene ring and the band near 2977 cm⁻¹ was the C-H stretching vibration peak of the benzene ring by Raman spectroscopy. The molecular structure of the synthesized polyamide compound was confirmed by FT-IR, Raman, and solid ¹³C-NMR spectroscopies. It was proved that the polymer is stable up to 300˚C and has a relatively high stability by the thermogravimetric analysis. It was also confirmed by the fluorescence spectrum that it has a strong blue fluorescence near 420 nm. The morphological characteristics of the polymer were further demonstrated by electron scanning electron microscopy (SEM). The properties of polymeric p-benzoyl-4,4'-diaminobenzoyl-aniline were found to emit strong blue fluorescence and have good thermal stability, making it a promising functional material for fluorescence in the blue region with potential for large-scale applications.