Application of chemically modified waste Allium cepa skin for one bath dyeing of polyester/wool blend fabric

Purpose The purpose of this paper is to highlight the one bath dyeing method for polyester/wool (PES/Wo) blend fabric with two different semi-synthetic azo dyes developed by chemically modifying the outer skin of Allium cepa. Design/Methodology/Approach Chemical modification is the most heartening way to impart improved properties to natural sources. Two different primary amines were coupled with the Allium cepa skin extract by a diazo coupling reaction. Synthesised dyes were characterized for their percentage yield, solubility tests, melting point, particle size analysis as well as FTIR spectroscopy and UV-Visible analysis. One bath dyeing methodology was used for application of synthesized dyes on PES/Wo blend fabric. Dyeing was performed at boil without any additional auxiliary and further percentage dye exhaustion was evaluated. Findings Dyeing yielded solid shade on PES/Wo blend fabric with satisfactory levelness in dyeing. The efficacy of synthesized dyes for dyeing of PES/Wo fabric was studied by wash, rub, light and sublimation fastness properties, which are in good agreement with commercial requirements. The antimicrobial activity of the synthesized dyes shows excellent activity in dye powder form (AATCC 147 test method) as well as on dyed fabrics (AATCC 100 test method). Originality/Value Present research work is a first successful attempt to dye PES/Wo blend fabric with semi-synthetic azo dyes in single bath at boil. Such approach facilitates minimum consumption of energy, cost and time.