Solvent-base mismatch enables the deconstruction of epoxy polymers and bisphenol A recovery

Fiber-reinforced epoxy composites are key materials for the construction of wind turbine blades and airplanes due to their remarkable mechanical strength properties. On the flipside, their physical and chemical inertness also results in a lack of viable recycling technologies. Recently, tailored resins have been introduced, which allow controlled fragmentation of the polymer matrix and thus the recovery of embedded fibres. However, for the separated thermoset epoxy fragments there is no recycling solution available, resulting in loss of complex molecular structures at their disposal. Here we report a chemical process for recovering bisphenol A (BPA) from epoxy resins, using a mismatched base-solvent system at an elevated temperature. We demonstrate a combinatory disassembly processes / chemical deconstruction strategy on a commercial tailored composite sample, isolating both fibres and the polymer building block. The recovered BPA could potentially be reused in established polymer production chains, thus closing the recycling loop and reducing the need for virgin resources.