Characterization and Application of Sikkam (Bischofia javanica Blume) as a Natural Dye and Antibacterial Agent for Eco-Printing Textiles

In Indonesia, some parts of the sikkam (Bischofia javanica Blume) plant, such as its roots and wood, are used for traditional flavors and medicine, whereas the remaining parts (twigs and leaves) are wasted. These wastes consist of polyphenols, which can act as dyes and antibacterial agents. One of the obstacles to applying natural dyes in textiles is color stiffness; hence, the mordanting step is essential. However, no comprehensive study of the application of sikkam twigs and leaf extracts in textiles has been reported. This study examined the optimization of several materials, including alum sulfate, ferro sulfate, and sodium acetate, and their combination with an eco-printing technique to fix their color. According to the elucidation of the structure by Py-GC/MS, twigs had more lignin compounds, while more lignin was present in the leaves (39%) than in the twigs (30%), which was correlated with their chemical composition. The relatively high lignin content of the leaf extracts results in greater antibacterial activity than that of the twigs against Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis, and Propionibacterium acne, with clear zones in the range of 0.6–0.7 cm. The textiles impregnated with sikkam extract (twigs and leaves) exhibited greater antibacterial activity than the natural linen did. Additionally, mordants, especially a mixture of alum sulfate, ferro sulfate, and sodium acetate, showed very stable antibacterial effects even after 80 washes. The mordant mixture of alum sulfate and ferro sulfate had the least effect on the color of the fabric dyed with the sikkam extract, with the lowest ΔE. However, the tensile strength of the textile was slightly lower during the mordanting process than that of the native textile.