Eco-friendly synthesis of coumarins using lemon juice as a natural catalyst and application as disperse dyes on polyester fabric

Abstract

An efficient, low-cost, and eco-friendly protocol has been carried out for the synthesis of two coumarin derivatives using lemon juice as an eco-friendly acidic catalyst. The chemical structures of these derivatives were characterized using melting points as well as spectral data (IR, NMR, and MS). By optimizing dyeing factors like time, temperature, and pH, the study's main goal was to ascertain how dispersion dyes 10 and 7 react when dyeing polyester fabrics. The colored polyester samples varied in color from light brown to yellowish brown to reddish brown to dark brown, depending on the coupler moieties at a depth of 5%. To achieve excellent colour strength in value (K/S = 21.7), the ideal dyeing conditions for dye 10 were 30 min, pH of 2, and 130 °C at shade 5%. While the ideal dyeing conditions for disperse dyes dye 7 (K/S = 20.8) were 30 min, pH of 4, and 130 °C at a shade of 5%. When everything is considered, synthetic dyes appear to be good choices for adding a variety of colors to polyester textiles.