Recyclable separation and recovery of carbon fibers from CFRP composites: Optimization and mechanism

Abstract

• Carbon fibers are recovered from CFRP via chemical swelling and electrochemical oxidation. • Solvent DMSO is recyclable in this separation and recovery method. • Recovered carbon fibers exhibit good surface morphology and mechanical properties. Chemical swelling and electrochemical oxidation are combined to realize the separation and recovery of carbon fibers from carbon fiber-reinforced plastic (CFRP) in dimethyl sulfoxide (DMSO) at normal temperature and pressure. The results showed that the depolymerization rate of epoxy resin in CFRP increased with increasing ammonium acetate concentration and current density, and the influence of the current density was more significant than that of the concentration. Microscopic analysis showed that the recycled carbon fibers had few residual resin on their surfaces and mild electrochemical oxidation etching, and recycled carbon fiber monofilament achieved a tensile strength and an interfacial shear strength that were 93.55% and 118.76% those of the original fibers.