Optimized bio-based epoxy composites with recycled fillers for sustainable noise mitigation

The growing demand for sustainable noise control solutions in construction and building materials has driven the development of bio-based epoxy composites incorporating recycled aluminium foil (RAlF), red mud, and recycled rigid polyurethane (RPU) powder. In this study, a wet-layup technique was employed to fabricate eco-friendly composites with enhanced acoustic properties while promoting circular economy principles for achieving net-zero carbon emissions. The composites were characterized using high-resolution scanning electron microscopy (HR-SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) to evaluate their morphology, chemical interactions, and thermal stability. Response surface methodology (RSM) with a central composite design (CCD) was utilized to optimize the material composition, identifying an optimal combination of 1 wt% RAlF, 15 wt% red mud, and 1 wt% RPU. The optimized composite exhibited a noise reduction coefficient (NRC) of 0.274. Acoustic simulations based on the Johnson-Champoux-Allard (JCA) model in COMSOL Multiphysics demonstrated a significant reduction in sound pressure levels, ranging from 9 to 54 dB across 200–2000 Hz. These findings highlight the potential of bio-based epoxy composites for use in soundproofing applications within buildings, offering an environmentally sustainable approach to noise mitigation while enhancing material performance.