Disintegration and Recycling of Multi-layered Glass Fiber Reinforced Polymer Composites via Superheated Steam

Abstract

To increase viability of recycling of robust and large-scale multi-layered glass fiber reinforced polymer composites (GFRPs), disintegration of the multi-layered GFRPs and recovery of fibers/resin-derived materials were investigated using superheated steam (SHS) under normal pressure where a very quick heat transfer to GFRP was possible. The SHS treatment of 4 different types of multi-layered GFRP products were conducted at 350 °C in an oxygen-free environment up to 3 hours. The SHS treated GFRPs were easily disintegrated into each layer. The separated layers were divided into components: glass fibers, oligomers, and inorganic fillers after subsequent thermal and ultrasonication processes. Finally, clear glass fibers were recovered, and matrix resin was also recovered as soluble oligomers consisting of phthalates, glycols, and styrene units due to partial chain cleavage of cured resin. These results clearly showed the viability for the recycling of actual large-scale multi-layered GFRP products.