Clean Process: Reducing indigo by using environmentally friendly 3-hydroxybutanone on dyed cotton modified with Denitex BC 200%

Abstract

Industrial processes in everyday life need to take into consideration environmental safety. This is the major goal of today's scientific research. Textile research is no exception. This paper illustrates a green process in which indigo is converted into its water-soluble leuco form by using a reducing agent that is ecologically friendly: 3-hydroxybutanone (C4H8O2). The effect of alkalinity and reducing temperature on the reducing power of C4H8O2 has been evaluated in the absence and presence of indigo. The dyeing quality of the modified cotton resultant of the exhaust process is studied. Cotton modification is carried out by using Denitex BC 200% in order to improve the quality of the exhaustion dyeing process. Modified cotton fibres are characterized through a morphology analysis (by using a SEM), Fourier transform infrared spectroscopy and X-ray diffraction analysis. The performances of the indigo dyeing process are evaluated by measuring the redox potentials generated in the medium with and without indigo, dyeing bath exhaustion (E(%)), and colour yield (K/S) of the coloured cotton at 660 nm, brightness index (B(%)) and dyeing fastness of both the untreated and modified cotton fabrics.