Application of Tectona grandis Leaf Extract for Efficient and Stabilized Coloration of Mulberry Silk Fabric

Abstract

Plant-based dyes are swiftly supplanting synthetic dyes due to their safe, eco-friendly nature, health benefits, and versatile applications. In this study, an attempt was made to explore the dyeing and functional finishing of mulberry silk using extracts from teak (Tectona grandis) leaves utilizing metal mordants. This method enhances the fastness properties, color strength, antibacterial activity, and UV protection ability of the silk fabric. Based on total polyphenols, flavonoids, and antioxidant activity, methanol/water/HCl was considered as the optimized solvent system for functional component extraction from teak leaves. The highest color yield was found to be in the methanol/water solvent system using HCl at pH 2.5 (K/S = 48.338) and temperature at 80 °C (K/S = 28.009) for a dyeing time of 45 min. The dyed silk with alum mordant exhibited good fastness properties (rating 4–5) and the UPF values were highest with silk dyed using a methanol/water/HCl solvent system (UPF = 56.10). The silk fabric showed good antimicrobial activity against Staphylococcus epidermis MTCC435 dyed with methanol/water and methanol/water/HCl solvent extracts using alum mordant. The bonding interactions were demonstrated by X-ray photoelectron spectroscopy (XPS). The study demonstrated that teak extracts are safe, abundant, and sustainable coloring agents appropriate for dyeing mulberry silk on an industrial scale.