Improvement of the Dyeability and Salt-Free Dyeing for Wool Fabrics with Anionic Dyes by Pretreatment with Whey and Soybean Proteins

Wool fabrics were pretreated with whey protein concentrate (WPC) and soybean flour (SPF) proteins individually to improve their dyeability toward anionic dyes as acid orange 10 (AO10) and reactive black 5(RB5). Comprehensive study was undergone on these fabrics evaluating their dyeability, functional properties and the possibility to reduce the need for electrolyte in the dyebath. Furthermore, coating with protein as a biopolymer is more environmentally friendly. The structure and properties of the pretreated wool fabric were evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ultraviolet spectroscopy (UV) and antimicrobial activity. Nitrogen content was used to confirm the existence of amino groups on treated protein fabrics compared to the untreated one. All the pretreated dyed samples were enhanced in color strength (K/S). The color strength of wool treated fabrics without salt was the highest. Treating fabrics indicated better protection against ultraviolet radiation and the highest UV protection factor (UPF) was of white and dyed wool fabrics treated with SPF. The highest antimicrobial activity reduction percent against gram positive bacteria (Bacillus cereus) was in the sample treated with WPC as well as the sample treated with SPF has the greatest antimicrobial activity effect against fungal yeast (Candida albicans).

Automated summary

In this study, wool fabrics were pretreated with whey protein concentrate and soybean flour protein to improve their dyeability towards anionic dyes and reduce the need for electrolyte in the dyebath. The pretreated fabrics showed enhanced color strength, better protection against ultraviolet radiation, and antimicrobial activity.