High-Performance Bio-Benzoxazine Resins Derived From Natural Renewable Vanillin: Synthesis, Characterization, and Properties of Their Thermosets

In this study, we used vanillin and furfurylamine from renewable resources as starting materials and successfully synthesized an innovative derivative of bisbenzoxazine (MH-fa) using the Mannich reaction. We characterized the chemical structure of the newly synthesized bisbenzoxazine compound using high-resolution mass spectrometry (HR-MS) technology. The results of nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy analysis (FT-IR) confirmed the successful synthesis of the target compound. The synthesis of the benzoxazine copolymer (MH-fa-co-DDM-BMI) was achieved by leveraging the reversibility of the Diels–Alder reaction between the MH-fa monomer and 4,4′-bismaleimide diphenylmethane (DDM-BMI). In addition, the investigation into the polymerization behavior of benzoxazine monomer and its corresponding main-chain copolymer was conducted employing differential scanning calorimetry (DSC) along with in situ FT-IR. We studied the thermal stability and combustion performance of two samples using thermogravimetric analysis (TGA) and microscale combustion calorimetry (MCC). The results revealed that the bio-based bisbenzoxazine exhibited excellent heat resistance and flame retardancy. Specifically, poly(MH-fa) exhibits a T d10 value of 350°C and a Y c value of 62.3% at 800°C. Furthermore, the material exhibits an extremely low heat release rate (20.4 J g −1 K −1 ), highlighting its potential applications in the field of high-efficiency flame retardant materials.