Natural Dyes Extract from Chinese Tallow ( Triadica sebifera) Tree Leaves Extraction in Alkaline Medium and Their Application on Silk Fabrics

Abstract

In this research work, natural dye was extracted from tallow plant in alkaline medium of extraction and was applied on silk fabric on exhaust dyeing process. Three mordanting techniques (pre-mordanting, meta-mordanting, and post-mordanting) were employed using aluminum potassium sulfate, ferrous sulfate, and zinc sulfate as mordants. The dyeing was conducted with and without metallic salt mordants. The color of dyed silk was investigated in terms of the CIELAB (L*, a*, b*, C*, and H*) and color strength (K/S) values. The color fastness to washing, light, and crocking of the dyed samples were measured according to ISO 105 C06, ISO 105-B02: 1994, and AATCC Test Method 8-2007, respectively. Optimum results were achieved when dyeing at 90℃ for 60 min and at pH 4. Silk fabric dyed without mordant had a shade of reddish-brown, while those mordanted with aluminum potassium sulfate, and zinc sulfate produced a variety of pale to dark reddish color shades. However, ferrous sulfate mordant gives duller and darker shade. The color fastness to washing was fair to good, whereas the color fastness to light was poor to fair, and colorfastness to crocking was good to excellent. The SEM analysis showed a very little damage to dyed silk samples at temperature near to boiling. The UV protection and antimicrobial property of the silk dyed with plant extract was studied. The results showed that the fabric samples treated with extract have excellent UV protection properties and are very effective in blocking UVA and UVB radiations. The fabric dyed with natural extract has tremendous antimicrobial activity which was proved by bacterial reduction in quantitative tests whereas the antibacterial activity of the control fabric was negligible.