Reuse of Recycled Short Glass Fibers for Enhancing the Flexural, Interlaminar Shear, and Fracture Performance of Glass/Epoxy Composites: A Sustainable Alternative

The recycling and reuse of glass fiber–reinforced epoxy composites remain significant challenges due to the thermoset nature of epoxy matrices, which limits conventional recycling routes. In this study, an effective reuse strategy for recycled short glass fibers (RSGFs) is proposed, contributing to the advancement of sustainable composite recycling and circular economy practices. The influence of incorporation of different concentrations (0.1, 0.3, 0.5, and 0.7 wt%) of RSGFs having length ~0.5–2 mm on the fundamental mechanical properties of virgin glass fiber epoxy composites (VGFECs) is explored here. Among all the RSGF concentrations, 0.3% RSGFs in VGFEC improved the flexural strength by ~18%, the flexural modulus by ~19%, and the interlaminar shear strength by ~22%. Simultaneously, significant improvements in both mode I and mode II interlaminar fracture toughness were observed, which were ~54% and ~30% respectively when VGFEC was reinforced with 0.3% RSGFs. Dynamic mechanical thermal analysis revealed that the storage modulus of 0.3 RSGF‐VGFEC was higher by ~20% than VGFEC. Fractography of specimens revealed interesting features like RSGF pull‐outs, shear cusps, fiber imprints, and marks of RSGFs.