Development of Fully Biobased High-Performance Bis-Benzoxazine under Environmentally Friendly Conditions

Environmental concerns are driving scientists in a quest for more sustainable products and processes. In the development of bis-benzoxazines, a novel class of thermosetting resins, which are receiving considerable attention from academia and industry, bisphenol A (BPA) and toxic solvents are still drawbacks that need to be overcome. Renewable feedstocks, neoteric solvents, and energy-efficient heating sources are sophisticated alternative solutions to the current traditional methodologies. In the current study, an eco-friendly approach to a fully biobased thermosetting resin from lignocellulose-derived products is reported. Catechol and furfurylamine are successfully fused into bis-benzoxazines in only a few minutes under microwave irradiation in the presence of poly(ethylene glycol) as solvent. The workup procedure requires minimum amounts of methanol for complete purification of the product in good yields, which is characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and H-1 and C-13 nuclear magnetic resonance spectroscopy (NMR). As used in the development of high-performance polymers, novel copolymerized polybenzoxazines are evaluated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA).