Polymerization behaviors and properties of benzoxazine resins based-on meta-substituted anilines

Abstract

The molecular structure of benzoxazine is closely related to its polymerization activity and the properties of its polymer. In this work, benzoxazines were successfully synthesized from phenol, paraformaldehyde and meta-substituted anilines. Their polymerization behaviors were discussed by non-isothermal differential scanning calorimetry (DSC). Moreover, the thermal properties of corresponding polybenzoxazines were evaluated using DSC and thermogravimetric analysis. The results showed that the electron-withdrawing substituent increased the polymerization temperature while the electron-donating substituent lowered the polymerization temperature. The glass transition temperature decreased for polybenzoxazine with electron-donating substituent but elevated for polybenzoxazine with electron-withdrawing substituent. Besides, the thermal stability and thermal degradation mechanism of polybenzoxazine were significantly affected by the substituent. This work supplied further insight in the structure-property relationship of benzoxazine resin.