Fully Bio-Based Epoxy-Amine Thermosets Reinforced with Recycled Carbon Fibers as a Low Carbon-Footprint Composite Alternative

Composites based on fully bio-based epoxy-amine resins reinforced with recycled carbon fibers were obtained and compared to petro- and partially bio-based benchmark materials. Rheology measurements showed that fully bio-based resins are better suited for resin infusion processes as they have higher gel-point temperatures than the benchmark formulations. Thermogravimetric analyses demonstrated that the resin thermal resistance was increased in the presence of recycled fibers. Dynamic mechanical analyses showed that the glass transition temperatures of fully bio-based composites are higher by 30 °C than other reported bio-based materials, making them better suited for industrial applications. Fully bio-based composites exhibited an improvement of mechanical properties between 5 and 85% compared to the benchmark materials. Indeed, a better fiber wetting behavior was observed by scanning electron microscopy analyses, enhancing fiber–matrix interfaces, resulting in higher mechanical behavior. This unprecedented work highlights fully bio-based epoxy-amine resins reinforced with recycled carbon fibers as a realistic low carbon-footprint alternative for functional applications.