Abstract

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Curcumin, a natural dye derived from turmeric, faces limitations in cotton dyeing due to its poor fibre affinity and inadequate fastness properties. This study systematically evaluates the enhancement of curcumin dyeing performance on cotton using three metallic mordants (alum, ferrous sulphate, and potassium dichromate) applied through pre-, meta- (simultaneous) and post-mordanting techniques. Dye exhaustion and fastness properties (wash, rubbing, and light) were assessed. Unmordanted cotton exhibited low dye exhaustion (45%) and poor fastness performance. Mordanting significantly improved dye uptake and fastness properties, with ferrous sulphate applied via pre-mordanting yielding the highest exhaustion (82%). Potassium dichromate and ferrous sulphate produced the most improved fastness results (wash fastness: 4–5; light fastness: 3–4). Among the mordanting techniques, pre-mordanting consistently demonstrated superior performance. The findings confirm that appropriate mordant selection and application strategy can substantially enhance curcumin dyeing, enabling its effective use as a high-performance and sustainable natural dye for cotton textiles, thus, offering a sustainable alternative to synthetic dyes.

Keywords: Curcumin, Exhaustion, Mordanting, Curcuma longa, Cotton fabrics