High-Performance Phthalonitrile Resins Partially Derived from a Furan Bio-Based Chemical Platform

Phthalonitrile resins are renowned for their outstanding heat resistance, withstanding temperatures exceeding 350 °C. This makes them highly sought after in industries such as aerospace, automotive, electronics, and renewable energy. To improve the sustainability of these materials, bio-derived phenols have been employed for the synthesis of the monomer in this research field. Thermosets derived from these partially bio-based monomers have demonstrated performance on par with their fossil-based counterparts, emphasizing the potential of sustainable phthalonitrile resins for advanced applications. Herein, the furan chemical platform is utilized to design and synthesize phthalonitrile monomers. Starting with furfural and its derivatives, novel low-melting (50-75 °C) Schiff-base monomers are synthesized and subsequently cured into thermosets. The resulting thermosets exhibit remarkable properties, including degradation temperatures (T_5%, determined by thermogravimetric analysis) above 450 °C (after curing at 350 °C), char yields (Y_c, at 900 °C) determined between 74 and 78%, and glass transition temperatures (T_g) surpassing 400 °C after curing at 350 °C and exceeding 300 °C after curing at only 250 °C. These findings underscore the versatility of furan chemistry in producing more sustainable phthalonitrile resins. The chemical design of these monomers enables the optimization of processability and material properties, broadening their application potential and advancing sustainability across multiple industries.