Biobased boronic ester vitrimer resin from epoxidized linseed oil for recyclable carbon fiber composites

In the last decades fiber-reinforced polymer composites (FRPC) have seen an enormous growth however, at the end of their lifetime, FRPC made of epoxy resins cannot be easily recycled because of the permanently crosslinked structure of the resins. Since the fibrous reinforcements usually have high costs, the possibility of developing recyclable FRPC is very advantageous both from environmental and economical point of view. To address this increasing need of the market, we developed a recyclable, environmentally friendly vitrimer resin from epoxidized linseed oil and a boronic ester cross-linker. Using the vitrimer as a matrix, carbon fiber-reinforced composites, with mechanical performance similar to the ones prepared with a conventional epoxy resin, were obtained. Moreover, the composites could be conveniently recycled under mild conditions by reversible hydrolysis of the boronic ester crosslinks using aqueous EtOH, recovering both the carbon fiber reinforcement and the vitrimer matrix.