Decomposition of waste carbon fiber reinforced epoxy resin composites in molten potassium hydroxide

Recycling of carbon fiber reinforced epoxy resin composites has been investigated using molten potassium hydroxide as reaction media. The epoxy resin in composites was decomposed at temperatures ranged from 285 to 330 °C. The recovered carbon fibers were characterized by SEM, XPS and single fiber tensile test. More than 95% of the tensile strength of the virgin carbon fibers was retained. The surface C-OH decreased and COOH increased with increasing temperature. The decomposition products of epoxy resin in KOH was separated and analyzed by FTIR and MALDI-TOF. A possible mechanism for the decomposition of epoxy resin is proposed. The real-world CFRP wastes containing various contaminants such as thermoplastics, paints, sealants and glass fibers were also decomposed in the molten KOH.