The objective of this research was to dye the silk fabric using triazine reactive dye C.I. Reactive Blue 71 modified with glutamic acid and with amino acids in the silk degumming solution. In the first case 0.5 g of reactive dye was modified with 1, 2, 3, and 4 g of glutamic acid, while in the second case 0.5 g of reactive dye was modified with 100 ml of the silk degumming solution (degumming 8 g of silk fiber). The modification in both cases was conducted at room temperature, 40 ℃, and 60 ℃, pH 9 for 0, 2, 4, 6, 8 and 24 hr. Finally, the modified and the unmodified dyes were used to dye silk fabric at 90℃, pH 3 for 45 min. FTIR and HPLC analyses indicated that the reactive dye could be modified with both glutamic acid and amino acids in the silk degumming solution. Dyed fabric was measured for color strength at a wavelength of 670 nm using a colorimeter and found that silk fabric dyed with modified dyes showed higher color strength than silk fabric dyed with an unmodified dye. In addition, it was found that dyeing of silk fabric using reactive dye modified with amino acids in silk degumming solution, produced a higher color strength of dyed fabric than dyeing of silk fabric using reactive dye modified with glutamic acid. However, silk fabric dyed with modified and unmodified reactive dyes showed a good colorfastness to washing while showed a moderate colorfastness to corocking.
