Transforming environmental sustainability: Lime treated used coffee grounds for innovative eco-friendly epoxy composite materials

Abstract

This study proposes an innovative method to recycle used coffee grounds into environmentally friendly epoxy composite materials while emphasizing the sustainability of this process. This approach focuses on using lime treated coffee grounds as a reinforcing agent for epoxy composites. Diverse analytical techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ther mogravimetric analysis (TGA) and mechanical testing according to international standards have been used to evaluate the properties of materials. Coffee grounds have been treated by soaking in Ca(OH)₂, solution with different concentrations (0.1 м, 0.3 M) and processing times (1, 3 and 5 days), then combined with epoxy resin to form composite materials. The results showed that using coffee grounds treated with Ca(OH)₂, significantly improved the stability and performance of epoxy composites. The best fire retardant performance was achieved with a Ca(OH)₂ solution with a concentration of 0.3. M. and a treatment time of 3 days, with a limiting oxidation index (LOI) of 21.6%. Furthermore, the compressive strength increased by about 20.79% compared to pure epoxy resin. This study highlights the potential of optimizing coffee grounds treatment parameters with Ca(OH)₂ to improve the properties and performance of epoxy composites, thereby promoting practical application and environmental protection.