Toward Sustainable Composites: Recyclability of Epoxy Vitrimer GFRPs and Enhanced Strength Retention Using MWCNT Filler

ABSTRACT Recycling glass fibers for structural applications involves reusing, repurposing, and recovering materials rather than discarding them after a single use, thereby reducing waste generation and supporting a circular economy model. This study investigates the recyclability of vitrimer‐based glass fiber‐reinforced polymer composites (GFRPs) and their ability to retain the strength of recycled composites as primary structural components. An epoxy–anhydride vitrimer matrix was used to fabricate GFRPs, and a chemical recycling process was employed to recover glass fibers by depolymerizing the vitrimer matrix in a mixed solvent system of dimethylformamide and ethylene glycol. The clean surface observed in the SEM micrograph and similar Raman spectral trends for both the virgin and recycled fibers confirm the effective recyclability. The GFRP laminates fabricated from these recycled glass fibers retained flexural and tensile strengths of approximately 95% and 98%, respectively, compared to the virgin glass fiber vitrimer composite. To enhance the strength retention, multi‐walled carbon nanotubes (MWCNTs) were incorporated into the vitrimer matrix which increased the strength retention to 99% and 103%, respectively. The results demonstrate effective recycling of glass fiber and retention of maximum strength, which ensures the use of recycled glass fibers for high‐end applications.