Multi-functional syringol based epoxides and properties of their thermoset polymers

Lignin-based syringol monomer, 2,6-dimethoxypropylphenol (DMPP), can be upgraded through two synthetic routes to multi-functional propylpyrogallol DMPPO. With three hydroxyl groups, DMPPO can serve as a renewable polymer building block. In this study, we describe the synthesis and characterization of DMPPO epoxide mixtures based on their synthesis methodology; one route uses HBr, another a greener methodology with Nb2O5 catalyst in water. Epoxy thermoset polymers using the two different epoxide preparations are synthesized, characterized, and contrasted. Optimization of reaction conditions, including temperature and catalyst concentration, to enhance the performance of epoxy thermosets is discussed. Through dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), the thermo-mechanical behavior and thermal stability of the resulting epoxy thermoset networks are evaluated, shedding light on how structural differences impact performance. Lignin-based syringol monomer, 2,6-dimethoxypropylphenol (DMPP), can be upgraded through two synthetic routes to multi-functional propylpyrogallol DMPPO and tri-epoxide which allows for various polymer applications.