Good Solvent Assisted Recycling of Thermosetting Polymers with Dynamic Bonds

Thermosetting polymers are a class of high-performance materials with significant industrial applications. However, reclamation of both industrial thermosets matrix and binding matter are significantly challenging. Recently, thermosetting polymers capable with bond exchange reactions provide a new opportunity. Here, we present a method to recycle thermosetting polymers efficiently by a synergistic effect of mixed solvents with a highly efficient organic catalyst at ordinary pressure and mild temperature. The network depolymerization enabled by selective bond cleavage process is substantially enhanced by a good solvent assisted and small molecule participated exchangeable reaction. At 170 ^oC under ambient pressure, we showed the epoxy thermosets can be dissolved in 28 min with 50% mass loss, and 70 min with 95% mass loss. We demonstrate that this method can be used to reclaim carbon fibers from industrial carbon fiber reinforced polymer composites and embedded metal parts from commercial electronic products with undiminished properties at mild temperature (~170^oC) under an ordinary pressure in a short time (1.5 hours). We also developed a modeling framework to probe into the complicated reaction-diffusion coupling and reveal the effect of reinforcement, such as carbon fiber, on the dissolution process of carbon fiber reinforced epoxy.