Novel Fully Biobased Benzoxazines from Rosin: Synthesis and Properties

In the present study, two novel fully biobased benzoxazines were synthesized using modified products of rosin, dehydroabietylamine, guaiacol, 4-methylumbelliferone, and paraformaldehyde. The chemical structures of DM (dehydroabietylamine, 4-methylumbelliferone) and DG (dehydroabietylamine, guaiacol) were characterized by Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (NMR) and 13C NMR spectra, dimensional nuclear magnetic and high-resolution mass spectrometry. The curing process of DM and DG was monitored by differential scanning calorimetry and in situ FTIR. The results demonstrated that the corresponding polymers PDM and PDG had high thermal stability. In addition, they had low dielectric constants below 3.30 at 25 °C and 1 kHz condition. Water contact angle measurements, OPC-time curves, and Tafel plots of PDG and PDM were also studied. The results showed that anticorrosion performances of PDG and PDM were stable during the immersion process and had strong abilities as shield corrosive media. Therefore, these two benzoxazine resins based on dehydrobietylamine may have potential applications in many fields.