Utilization of Pterocarpus marsupium Sawdust as a Natural Dye Source for Cotton Fabric Dyeing

Abstract: In the pursuit of sustainable and eco-friendly alternatives to synthetic dyes, this study investigates the viability of Pterocarpus marsupium sawdust as a natural dye source for cotton fabric. Natural dyes, being biodegradable and non-toxic, are experiencing renewed interest due to increasing environmental concerns. The dye was extracted from Pterocarpus marsupium sawdust using aqueous extraction, and the extraction parameters such as concentration, time, and temperature were optimized for maximum dye yield. The dye was then applied to desized cotton fabric, and dyeing conditions were similarly optimized for time, dye concentration, and material-to-liquor ratio. Mordanting techniques were employed to improve colour fastness, using both alum and bio-mordants. Characterization of the dye was conducted using UV-Visible spectrophotometry, FTIR, phytochemical analysis, and TGA. The dyed fabrics were evaluated for colour strength, fastness to washing, sunlight, crocking, and mechanical properties. The results indicate that Pterocarpus marsupium dye provides rich reddish-brown hues with good fastness and antimicrobial properties, making it suitable for applications in apparel and functional textiles. This study demonstrates the potential of utilizing sawdust, a wood industry by-product, as a sustainable dye source, thereby promoting circular economy practices and reducing environmental impact.