Pomegranate fallen leaves as a source of natural dye for mordant‐free dyeing of wool

Abstract

The application of metal mordants is usually necessary in dyeing of wool with natural dyes to improve the dye exhaustion and fastness properties. The majority of metal salts generally used as mordants are considered as toxic and it is important to find replacements for them. Plant sources with high content of tannins are good candidates as bio‐mordant or colourant to overcome this drawback. In this study, the waste fallen leaves of pomegranate tree were used as a source of natural dye for the eco‐friendly dyeing of wool fabric without the use of metal mordants. The dyeing process variables including dye concentration, dyebath pH, and temperature were optimised using response surface methodology to obtain the highest colour strength. The colour strength was increased by increasing the natural dye powder up to 100%owf while the optimum pH and dyebath temperature were 4 and 100°C, respectively. The sample dyed under the optimal condition exhibited good fastness properties against washing and light. This study approved the potential of Punica granatum fallen leaves for the dyeing of wool without any mordant, while high fastness properties were obtained.

Enhancing Starch−Based Packaging Materials: Optimization of Plasticizers and Process Parameters

“…Furthermore, the normality of the residuals is assessed through a normal probability graph of the residuals. When the number of models is adequate, the overall shape of the residual graph should resemble a straight line if the residuals follow a normal distribution [46]. Figure 11a,b displays the normal probability plots of the residuals for tensile strength and rebound rate, respectively.…”

Valorisation of sulphonated lignin as a dye for the sustainable colouration of wool fabric using sustainable mordanting agents: enhanced colour yield, colourfastness, and functional properties

“…Natural dyes are flavonoids, anthocyanidins, carotenoids, quinonoids, benzoquinone, naphthoquinone and anthraquinoids. Tannins are flavonoids extracted from the bark of various plants including Biancaea sappan , 6 cinnamon, 7 Ziziphus , 8 and Dalbergia sissoo , 9 leaves of Berberis thunbergia , 10 and pomegranate, 11 flowers of Hibiscus sabdariffa , 12 Hibiscus rosasinensis , 13 Crocus sativus , 14 and skins/peel of Citrus sinensis L. 15 The natural dyes extracted from fruits studied for wool fibre dyeing may include myrobalan, 16 chamomile, 17 peanut shell, 18 and anthocyanin pigments extracted from the peel/skins of various fruits, including red cabbage, 19 and dragon-berries. 20 Tannins and other flavonoids are advantageous as some of them have antioxidant and antibacterial properties that make the treated fabric multifunctional.…”

Valorization of Sulfonated Kraft Lignin as a Natural Dye for the Sustainable Dyeing of Wool Fabrics: Effect of Peroxide Oxidation

“…Tannins extracted from barks of various plants, including Ziziphus, cinnamon, walnuts, Azolla pinnata extract, and Cassia reingera, were found suitable for the dyeing of wool fiber. Natural dyes extracted from leaves of pomegranate, Berberis thunbergia, hibiscus flowers, Hibiscus rosa-sinensis, Crocus sativus, skins/peel of Citrus sinensis L., and various fruits, including myrobalan, chamomiles, and peanut shell, are also studied as an alternative to synthetic dyes. Anthocyanin pigments extracted from peels/skins of various fruits, including Brassica oleracea L., purple sweet potatoes, red cabbages, and dragon berries, have been studied for the dying of wool that produces a variety of colors.…”