Bifunctional Biomass-Based Benzoxazines with Double Bonds in Centrosomes: Synthesis, Curing Behaviors, and Kinetics

Benzoxazines are synthesized by combining amines or phenolic structures from renewable biomass to achieve high carbon yields and heat resistance, and they have attracted considerable attention as sustainable high-performance polymers. A bifunctional benzoxazine monomer (DES-fa) was synthesized from diethylstilbestrol and furfurylamine by a solution process and was cured and characterized. The structural composition of the DES-fa monomer was analyzed by NMR, Fourier infrared spectroscopy, and mass spectrometry. Curing kinetics were studied by differential scanning calorimetry (DSC) by employing the Kissinger, Ozawa, Starink, and Friedman methods. The apparent activation energy of DES-fa was calculated to be 110.81 kJ/mol using the Starink method. The predicted plots of the developed mathematical model aligned well with the experimentally obtained DSC thermogram results. A polymerizable group (oxazine, furan ring) was introduced into the benzoxazine molecule to reduce the curing polymerization temperature. Thermogravimetric analysis showed that the prepared benzoxazine resin exhibited excellent thermal stability, with a Td5 of 362 °C, a Td10 of 433 °C, a residual carbon content of 51%, and a Tg of 260 °C. Therefore, this new furfurylamine biobased benzoxazines offers a wide processing window and excellent thermal stability, which promise great potential for high-performance polymeric materials.