Synthesis and Polymerization of the Bio‐Benzoxazine Derived from Resveratrol and Thiophenemethylamine and Properties of its Polymer

• Published in: Macromolecular chemistry and physics Vol. 225; no. 19
• Main Authors: Zhong, Min, Yin, Ren, Sun, Zichao, Jiang, Tianjia, Sheng, Weichen, Zhang, Kan
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-10-2024
• Subjects: benzoxazine; Benzoxazines; Chemical synthesis; Energy value; Enthalpy; Fire resistance; Flow stability; Fourier transforms; Heat release rate; Heat transmission; Infrared spectroscopy; kinetics; Monomers; Polybenzoxazines; Polymerization; Reaction mechanisms; renewable resources; resveratrol, thermal stability; Structural analysis; Thermal stability; Thermogravimetric analysis
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.202400173

Resveratrol and 2‐thiophenemethylamine have been employed in the synthesis of a novel tri‐functional benzoxazine (RES‐th) to develop the bio‐benzoxazine monomer. The chemical structure of the synthesized monomer is confirmed by various characterization technics. The polymerization behavior is monitored by in situ Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The in situ FTIR results reveal distinct reaction mechanisms for the three oxazine rings presented in RES‐th, with both ether and phenolic Mannich bridge structures observed in the products. The activation energy values of RES‐th are calculated to be 119.05, 120.97, and 119.44 kJ mol−1 by Kissinger, Ozawa, and Starink methods, respectively, which are all based on the heat flow curves at various heating temperatures. The thermal stability and flame retardancy of the resulting polybenzoxazine (poly(RES‐th)) are investigated by thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC). The values of Td5 and Td10 of polybenzoxazine are found to be 356 °C and 399 °C, respectively, with a char yield of 66.3% at 800 °C. The prepared polybenzoxazine also demonstrates nonflammability characteristics with the values of heat release capacity (HRC) and total heat release rate (THR) of 18.65 J (g K)−1 and 2.69 kJ g−1, respectively. These findings suggest that the thermoset, poly(RES‐th), is a promising candidate for fire‐resistant applications.
A new tri‐oxazine ring‐containing thermosetting resin has been synthesized based on resveratrol and 2‐thiophenemethylamine. The polymerization kinetics have been systematically investigated by Kissinger, Ozawa, and Starink methods. The polybenzoxazine derived from the tri‐benzoxazine exhibits excellent thermal stability and flame retardancy, appointing this newly obtained resin as a promising candidate for fire‐resistant applications.