Abietic Acid Derivatives Combining Epoxy and Anhydride Functionalities: Self- and Co-Polymerization toward Fully Bio-Based Thermosets

We report the original synthesis of two abietic acid derivatives, epoxidized maleopimarate oleylamide (<b>EMPOA</b>) and epoxidized maleopimarate undecenamide (<b>EMPUA</b>), which uniquely combine epoxy and anhydride functions within a single molecular structure. Their ability to undergo self-polymerization was first investigated, and fully cross-linked thermosets were subsequently obtained by copolymerizing <b>EMPOA</b> and <b>EMPUA</b> with a series of commercial biobased epoxides derived from vanillin, glycerol, and vegetable oils. A key advantage of <b>EMPOA</b> lies in its excellent miscibility with epoxidized vegetable oils, providing low-viscosity mixtures that can be readily blended with other epoxy resins without requiring large amounts of solvent. Epoxidized soybean oil (<b>ESBO</b>) proved to be an efficient reactive diluent, reducing solvent use to trace levels. Cross-linked materials with glassy-state moduli in the gigapascal range, comparable to fossil-based thermosets, were obtained. These results establish <b>EMPOA</b> and <b>EMPUA</b> as promising dual-reactive monomers for the design of high-performance and fully biobased thermosetting materials.