Implementing recyclable bio- and CO <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si6.svg" display="inline" id="d1e1527"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:math> -sourced synergetic

The use of thermosets in natural fiber composites (NFC) presents major challenges related to their sustainability. Most alternatives struggle to meet industrial requirements relevant to conventional composite processing techniques. This study explores a synergetic copolymerization strategy that combines epoxy and CO 2 -derived polyhydroxyurethanes (PHU) to allow fine-tuned polymerization kinetics, including the suitability for the RTM process. We demonstrate a synergetic catalytic effect that accelerates curing compared to each neat component. The formulation maintains a low viscosity ( < 5 Pa.s) at room temperature while curing within 30 min at 80 ° C, unattainable conditions with pure PHUs. Formulations suitable for resin transfer molding (RTM) were developed and demonstrated an improvement in mechanical performances compared to the homopolymer parents. RTM-made composite achieved a fiber volume fraction of 58-60% and a porosity below 1%, making them ideal for high-quality NFCs. The influence of hybridization content was investigated, and the influence of impregnation quality was highlighted while the PHU well-supported the adhesion quality. Moreover, the catalyst-free dynamic matrix allows the reshaping after curing, and flax fibers can be easily separated without toxic reagents from the polymeric matrix under mild conditions ( 60 ° C for 2 h) and reused, retaining properties similar to those of virgin yarns. This strategy could broaden the application of PHU chemistry in sustainable NFC manufacturing while preserving both natural and fossil feedstocks. • A synergetic hybridization is reported for high-performance sustainable materials. • An auto-catalytic behavior between epoxy and PHU is reported to ease the curing. • High-performance biobased composites can be manufactured by RTM in a fast process. • The synergetic dynamic network allows the composite to be reshaped. • Natural fibers are fully recycled from the composite with no major degradation.