Comparative study of dyeing properties of two yellow natural pigments—Effect of enzymes and proteins

Biohydrolysis of nylon 6,6 fiber with different proteolytic enzymes

“…A great many studies have been carried out on the application of enzymes on natural fibers, including cotton surface modification to enhance the handling and appearance [5][6][7]; removing undesirable byproducts from the unscoured cotton [5]; desizing by enzymatic hydrolysis [3,5]; enzyme treatment of bleaching effluent [8,9]; softening woody fibers during retting [10,11]; shrink-proofing, softening, improving dyeability and pilling behavior of wool [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] and silk degumming [30,31].…”

Dyeing properties of Bombyx mori silks grafted with methyl methacrylate and methacrylamide

“…14 The percentage dye uptake, as shown in Table I, indicated that slightly greater dye uptakes were obtained from the MMA-grafted and MAA-grafted silks, regardless of the use of the potassium aluminum sulfate mordant. This is possibly because the MMA and MAA monomers, presented in the grafted silk molecular structures, caused not only the volume expansion of the amorphous region but also dipole-dipole interactions, hydrogen bonding, and Van der Waal's forces between the MMA and MAA side groups and the curcumin dyestuff, which contained carbonyl, hydroxyl and methoxy groups.…”

“…This is possibly because the MMA and MAA monomers, presented in the grafted silk molecular structures, caused not only the volume expansion of the amorphous region but also dipole-dipole interactions, hydrogen bonding, and Van der Waal's forces between the MMA and MAA side groups and the curcumin dyestuff, which contained carbonyl, hydroxyl and methoxy groups. 14 Generally, mordants, salts of inorganic elements such as aluminum, iron, and copper, are used together with natural dyestuffs to improve not only interactions between natural dyestuffs and fibers by the formation of complex molecules but also colorfastness properties. 19 When the mordant was used during curcumin dyeing, the degummed and both of the grafted silks had greater percentage dye uptakes compared to that of those dyed without the mordant because complex molecules could be formed among the dyestuff, MMA-grafted or MAA-grafted fibroin, and mordant molecules.…”

“…This yellow colorant has been used as a natural dyestuff and also as a food colorant. 14,15 Nevertheless, a problem that arises with natural dyes is poor fastness properties, especially light fastness. 16,17 Because the colorfastness properties of degummed silks have to be improved, the grafting process with vinyl monomers is considered an interesting technique.…”

Saffron

“…It is therefore being used to dye high-quality textiles manufactured with silk, cotton or wool (Takaoka et al, 1992;Tsatsaroni and Eleftheriadis, 1994;Liakopoulou-Kyriakides et al, 1998;Tsatsaroni et al, 1998). It is also used to dye rugs, hats and traditional clothes in Sardinia.…”