Luminescent polybenzoxazine: Synthesis, characterization, and photophysical properties

Abstract Polybenzoxazines are a class of luminescent polymers that exhibit light emission properties, making them suitable for various applications. This manuscript presents the synthesis, characterization, and thermal behavior of a novel luminescent polybenzoxazine, named P‐BZ‐CP. The synthesis of P‐BZ‐CP involved a three‐stage process, starting with the formation of Bis‐OHOMe through the reaction of cyclopentanone and vanillin, followed by a Mannich condensation reaction with p‐toluidine to obtain the monomer M‐BZ‐CP. Thermal ring‐opening polymerization of M‐BZ‐CP at 250°C resulted in the synthesis of P‐BZ‐CP. Comprehensive characterization techniques, including NMR, FTIR, XRD, SEM, TGA, and DSC, were employed to analyze the structure and properties of both M‐BZ‐CP and P‐BZ‐CP. The thermal behavior of M‐BZ‐CP curing was investigated using DSC, highlighting the temperature‐dependent polymerization process. This work also provides insights into the photophysical properties of Bis‐OHOMe, M‐BZ‐CP, and P‐BZ‐CP, highlighting the role of molecular structure and concentration in determining absorption, excitation, and emission characteristics. The core benzylidene cyclopentanone chromophore contributes to the common absorption and emission features, while the additional functional groups in M‐BZ‐CP lead to concentration‐dependent photoluminescence behavior due to aggregation or excimer formation. These findings demonstrate the importance of understanding the structure–property relationships in designing optoelectronic materials with tunable photophysical properties. The findings demonstrate the successful synthesis and characterization of luminescent polybenzoxazines, providing valuable insights into their potential applications in optoelectronics.