Characterization and dyeing potential of colorant-bearing plants of the Mayan area in Yucatan Peninsula, Mexico

Natural dyes are receiving increasing attention from researchers and manufacturers, given its perceived eco-friendly nature. Yet, adjunct agents known as mordants that help bond the molecules of the fabric being dyed and the colorant used to dye it are often toxic. There is scant published information describing the dyeing potential and toxicity of colorant-bearing plants and the dye uptake with respect to the mordant treatments. A preliminary survey based on a range of sources of information showed that of the Yucatan peninsula harbors 23 plants showing dyeing properties. Four of them (Justicia spicigera, Bixa orellana, Bougainvillea glabra and Rhoe discolor) were selected to extract their natural dyes, which were chemical and toxically characterized. B. orellana was successfully employed to dye the fabric, viz. ordinary cotton cloth, manta. The dye baths without mordant only present low toxicity, the J. spicigera and B. glabra dyes being the most toxic. The B. orellana dye was less toxic, although its toxicity is increased when mordants are used. Regarding color performances of the dyed fabrics, mordanting influenced the depth of the shades, improving dyeing and light fastness. Nevertheless, mordants had no significant effects on color values. (C) 2014 Elsevier Ltd. All rights reserved.