Extraction, Characterization, and Application of Natural Dye Derived from Hibiscus Sabdariffa on Cotton & Wool

The widespread use of synthetic dyes in the textile industry has led to significant environmental and health concerns due to their toxicity and non-biodegradability. This paper explores the potential of Hibiscus sabdariffa as a sustainable alternative by focusing on its extraction, characterization, and application as a natural dye on cotton and wool fabrics. The dye was extracted using a Soxhlet extraction method with methanol at a 1:4 solid-to-solvent ratio for 48 hours, followed by concentration, filtration, rinsing, and drying for 8 hours. The yield of the dye was 0.5 percent from 900 g of dried petals. Characterization involved UV–Visible spectroscopy, which revealed an absorption maximum at 520 nm, indicative of anthocyanins, and FTIR analysis, confirming the presence of phenolics, flavonoids, and carbohydrate-based compounds. The dye was applied to cotton and wool fabrics using three mordants: aluminium sulfate, ferrous sulfate, and copper sulfate. The dyeing was carried out at a controlled temperature of 100°C. The exhaustion rates showed that wool absorbed more dye (35.90–39.11 percent) compared to cotton (22.00–26.40 percent), with aluminium sulfate providing the highest exhaustion for both fabrics. Fastness tests indicated that cotton fabrics dyed with aluminium sulfate had wash fastness ratings of 4–5, while wool fabrics had ratings of 4. The study highlights that Hibiscus sabdariffa offers a viable, eco-friendly dye with moderate to good fastness, paving the way for more sustainable textile practices.