Phthalonitrile and propargyl ether from magnolia bark extract blended into processable thermosetting resins for high‐temperature applications

Abstract Phthalonitrile (MOPN) and propargyl ether (MOPE) thermoset resins were synthesized directly from magnolia ( Magnolia officinalis ) bark extract (MO), a natural product commonly used as a nutritional supplement. The synthesized resins showed good processability (low viscosity) and high decomposition temperatures compared to other previously reported resins of the same class. Blends of MOPN and MOPE were then prepared, cured, and characterized. The MOPN and MOPE resins as well as their blends were evaluated for cure kinetics in the uncured state and thermal stability in the cured state. The resin blends showed excellent low‐temperature viscosities (0.4 Pa s at 75 °C) and char yields ≥ 70% in air (600 °C) that matched those of MOPN despite high loadings of the lower char resin MOPE. The high char yields were unexpected based on the rule of mixtures and thus represent a significant improvement for low‐temperature processing of high‐temperature polymers and polymer matrix composites. © 2026 Society of Chemical Industry.