Development of sustainable microwave-based approach to recover glass fibers for wind turbine blades composite waste

In this study, we report the development of a sustainable microwave-assisted chemical recycling process to recycle glass fiber reinforced polymer (GFRP) composite waste. Degradation of GFRP composites using hydrogen peroxide and acetic acid with microwave irradiation was investigated. Process parameters: Chemical solvent to composite weight ratio (mL/g) and microwave exposure duration were used at constant microwave power (700 W). The chemical solvent ratio (oxidizing agent/acid:30/70, 50/50) with microwave exposure of 180 s could achieve nearly complete degradation of epoxy. The decomposition rate (Dy) of epoxy was found as 97.2%. TGA and FTIR analysis was done to determine Dy and basic chemical structure of recovered glass fibers (RGFs), respectively. SEM analysis was done for surface morphology of virgin glass fibers (VGFs) and RGFs. The RGFs showed 99.8% ultimate tensile strength, 93.3% Young's modulus, and 95.7% strain-to-failure compared to VGFs. A plausible mechanism for the degradation of matrix material has been proposed.