Physico-chemical study of dyed wool: Part I-Bougainvillaea as wool colourant with mixed mordant

Abstract

<span style="font-size: 14.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">The extract of red petaloid bracts of bougainvillaea has been used as wool colourant with mixed mordants and the physico-chemical properties of the dyed samples studied. The petaloid bracts when treated with water at 97.5°C for nearly

<span style="font-size: 14.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">20 min yield 7.43% of bougainvillaea (BV) colourant. The optimum conditions for dyeing of wool have been determined as pH 4.5, BV concentration 0.06 g per gram of wool, temperature 97.5°C, and time 45 min. It is observed that the use of lanthanum (III) as first mordant and chromium (VI) as second mordant reduces the quantity of Cr (VI) in the spent dye bath and causes less damage to the wool fibre in comparison to the dyed yarn mordanted with Cr (VI) alone. This binary mixed-mordant dyeing also reduces the environmental pollution caused due to the discharge of toxic chromium ion in the effluent.

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