Deposition of Functionalized Polyethylenimine-Dye onto Cotton and Wool Fibres

Functionalized polyethylenimine–dye (FPEI) is prepared by mixing branched polyethyleneimine (PEI), in which its primary amine groups are modified at different ratios with a quaternary ammonium coupler (QI), and reactive dyestuff (RD) (QI/RD = 0/100, 20/80, 40/60, 60/40 and 80/20 mole/mole %). The deposition of FPEI from an aqueous solution onto the surface of cotton and wool fibres is studied. The adsorption of a charged polymer from an aqueous medium by cotton and wool fibres is investigated at different pH values, and the uptake of colour on fibres is measured by Datacolor and UVVIS spectrophotometers.

The study of the kinetics of adsorption shows that pseudo-first-order kinetics provide the best correlation of the experimental data. The equilibrium data indicate that the deposition process onto both cotton and wool follows the Langmuir isotherm. In terms of colour strength (K/S value) the coated fibres compare well with those dyed with a commercial dyestuff, C.I. Basic Red 51, which suggests that the coating is a good alternative to classical dyeing.