Effect of Alkali Treatment on the Chemical Composition and Dyeability of Sisal Fibers

Recently, natural fibers have gained significant attention from many researchers due to the global demand for natural products with low environmental impacts. Sisal (Agave Sisalana), is among the important natural fibers with substantial potential to flourish due to their outstanding properties, including high strength, good absorbency, and abundant availability. However, utilization of these fibers is yet to be fully explored, probably due to their stiff and coarse nature, which limits the overall applications of this sustainable fiber. This study, therefore, investigated the effect of alkali treatment on the chemical composition and dyeability of sisal fibers as a way of adding value to the fiber and potentially broadening their applications. The findings of this study have shown that alkali treatment decreased significantly the amount of hemicellulose and lignin from 10.6% and 10.7% to 4.9% and 6.4%, respectively. However, the cellulose content slightly increased from 64.6% to 64.7%. The decrease in amounts of hemicellulose and lignin was thought to be due to their high sensitivity to the action of alkali. Furthermore, the chemical treatment improved the dyeability of sisal fibers when both reactive and vat dyes were used, resulting in fibers with higher levels of dye exhaustion and improved wash fastness properties. Overall, the results suggest that alkali treatment not only modified the surface structure of sisal fibers but also improved their dyeability with both reactive and vat dyes. This will contribute to expanding the practical applications of sisal fibers, making them more viable for use in sustainable textile production in future Keywords: Sisal fibers, Alkali treatment, Reactive dyes, Vat dyes, Colorfastness