Effects of Recycling on the Elevated Temperature Bending and Creep Response of Regenerated Glass Fiber Reinforced Epoxy Composites

ABSTRACT The surging global demand for Glass Fiber Reinforced Polymer (GFRP) composites across various sectors has led to significant waste generation, necessitating efficient and sustainable recycling techniques. Though several studies have reported the mechanical performance of either recycled glass fibers or regenerated glass fiber epoxy composites (RGFECs) at ambient temperature, their mechanical behavior under elevated temperatures remains insufficiently investigated. This study evaluates the flexural and creep behavior of RGFECs across different temperatures. The recycled glass fiber (RGFs) fabrics were obtained after 6 cycles, each cycle consisting of an optimized 7.5 min microwave irradiation phase and cooling phase, in a peracetic acid medium. As anticipated, the flexural strength of virgin glass fiber epoxy composites (VGFECs) is higher than that of RGFECs by 13%, 10%, and 28% at 50°C, 70°C, and 100°C, respectively. Further, creep testing revealed a higher temperature sensitivity of RGFEC composites in comparison to VGFEC. When the testing temperature was increased from 50°C to 70°C, the instantaneous creep strain of VGFEC and RGFEC increased by ~11% and ~23%, respectively. Further increase from 70°C to 100°C showed a negligible effect on VGFEC, whereas for RGFEC, it was increased by ~44%. The steady‐state strain rate of RGFEC is higher than that of VGFEC by ~280% and ~305% at 50°C and 70°C, respectively. Topography and fractography were conducted to study the RGFs' surface morphology and flexural failure modes at elevated temperatures. This study underscores the necessity for further optimization of recycling techniques to produce durable RGFECs in thermally demanding applications.