Synthesis of Bio-Based and Intrinsically Flame-Retardant Benzoxazine Containing Dynamic Ester Bond that Quantitatively Satisfies All Twelve Principles of Green Chemistry

An intrinsically flame-retardant benzoxazine resin is designed using natural renewable raw materials. The materials and synthesis conditions are designed to improve safety, greenness, and sustainability in the spirit of the 12 Principles of Green Chemistry. A synthetic condition is developed for a 99% yield of a biobased, ester-functional bisphenol preparation. A statistical mixture of furfurylamine and ethanol amine-terminated asymmetric benzoxazine with bis-furfurylamine and bis-ethanol amine-terminated benzoxazines is synthesized to improve processability by preparing a liquid resin. The terminal -OH group exhibits a catalytic effect, and low activation energies of 48.6-53.4 kJ/mol are observed for the polymerization of the isomeric mixture resin. The activation energy for the degradation of cross-linked polybenzoxazine using the Flynn-Wall-Ozawa equation is also determined. The transesterification mechanism is used for vitrimer formation. All of the Principles of Green Chemistry are addressed and justified for the monomer synthesis reactions. This paper represents one of the earliest, if not the first, examples of purposefully designed material development to fulfill all 12 Principles of Green Chemistry, and further evaluate the degree of greenness quantitatively.