Renewable bis-benzoxazine from symmetrical vanillin-based dimer

A novel renewable bis-benzoxazine has been created using a Vanillin-based dimer, furfurylamine and paraformaldehyde through a Mannich reaction. The Molecular structure of the synthesized bis-benzoxazine monomer was analyzed using Nuclear Magnetic Resonance spectroscopy and Fourier Transform infrared spectroscopy. The curing behavior of the bis-benzoxazine was evaluated by Differential Scanning Calorimetry and in situ FT-IR. The curing reaction exhibited a peak temperature of 228°C and a relatively low heat of reaction at 85 J/g. The thermal stability of the resulting polybenzoxazine was examined using thermogravimetric Analysis (TGA), which indicated a low degradation rate between 300°C and 800°C, along with a high char yield at 800°C. Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) analysis revealed that the primary pyrolysis products of polybenzoxazine were phenol and furan derivatives.