Green fabrication of cellulose-rich agricultural residues for scalable and biodegradable acoustic boards

Abstract

Enormous amounts of agricultural residues in India are often burnt or dumped in nearby areas causing air, land, and water pollution. Towards fitting in a green life cycle, in this work, we demonstrate the fabrication of acoustic boards from cellulose-rich agriculture residues (rice straw, bagasse, banana stem, and water hyacinth) by a combination of mechanical and chemical pulping processes, and the addition of a foaming agent. Electron microscopy revealed that the fabricated acoustic boards had a porosity > 80%. The boards comprised microfibers of diameter 15 μm, which are finer than the conventional boards made from natural fibers. The addition of a foaming agent increased the absorption coefficients of agroboards of rice straw and water hyacinth by a maximum of 100%, and by 200% for the agroboards of bagasse and banana stem, respectively, in some spectral regimes. In contrast, the transmission loss either remained the same or decreased due to the addition of a foaming agent. In conclusion, this work provides a path to develop scalable green fabrication of agriculture residues to develop efficient biodegradable acoustic boards.