Extract of Centella asiatica leaves as a biomordant in cotton dyed with natural dye Bixa orellana

Abstract

Natural dyeing is a promising process to reduce environmental pollution caused by the use of synthetic dye. Seed of Bixa orellana (Kesumba) contain bixin compound which can be extracted to give a beautiful orange color in textile. The application of B. Orellana seed extract to textile, especially cotton, is limited by their low color fastness. To help dye fixed in cotton fiber, mordant from metal salt is usually applied, but metal based mordant can promote severe pollution to the environment. In this study, extract of B. orellana seed was used as a natural dye and extract of Centella asiatica leaves (Pegagan) were used as a biomordant in cotton dyeing. Both raw materials were extract using water as a solvent. Tannin contained in Centella leaves could give a mordanting effect in cotton. Influence of Centella concentration (50, 150, 250 gr/L) and pH (4, 6, 8) during mordanting process (fixation) were studied and were compared with the use of Alum mordant. Response Surface Methodology (RSM) with the help of Minitab 16. Was used for optimization of the mordanting process. Color strength (K/S), wash fastness and light fastness property of each sample were evaluated. Functional group present in samples dyed were analyzed with Fourier Transfer Infra-Red (FTIR). In general, mordanting with Centella leaves extract can increase wash and light fastness (scale 3 to 3-4) of dyed sample without losing orange color character of Bixa, compared with non-mordant sample (3). Mordanting in pH 8 give highest color strength K/S, followed by pH 4 and pH 6. This whole process of dyeing and mordanting with natural resource will conduct the development of sustainable technology in textile industry.