Innovative isolation of colorant from Butea monosperma for surface-modified silk dyeing

Abstract

Recently, there has been a surge of interest in adopting natural dyes to avoid the environmental difficulties connected with synthetic coloring compounds. This research focuses on extracting natural dyes from Butea monosperma plants and on developing sustainable dyeing methods for silk fabric. Natural colorants were extracted using an aqueous and an acidic extraction procedure, and silk fabrics were dyed with the extracts using mordanting with a variety of metal mordants and bio-mordants. The treatment of fabric and extracts was carried out using microwave (MW) irradiation. It was found that the bio-mordants have shown higher color strength than metallic mordant. It was also observed that the acacia and pine nut hull at 80°C and before dyeing pomegranate extract at 80°C and after dyeing of silk fabric at 40°C using bio-mordants gave higher color strength than metallic mordants. For comparative analysis, aluminum (Al) salt at 40°C, iron (Fe) salt at 60°C and tannic acid at 80°C gave acceptable results. The colorfastness characteristics were also found good to excellent. The bio-mordants not only provide the higher color strength and fastness properties, but these extracts have also shown an environmental friendly approaches. Scanning electron microscopy image and Fourier transform infrared spectroscopy analyses revealed the difference between irradiated and unirradiated silk fabrics. Therefore, it is recommended that MW rays and bio-mordants should be used in the natural dyeing of silk fabric to produce colorfast shades of acceptable strength.