Enzymatic dyeing and functional finishing of textile fibres with ferulic acid

Abstract

The catalyzed polymerization of ferulic acid (FA) by laccase from Rhus vernicifera has been studied, and its polymeric products are used for the dyeing and functional finishing of silk, wool, nylon, viscose and cotton fabrics by two methods, namely simultaneous enzymatic polymerization of FA and dyeing at 50 ^oC (one-step method), and enzymatic polymerization of FA at 50 ^oC followed by dyeing at 90 ^oC (two-step method). The analyses of UV-Visible and FTIR spectra show the formation of yellow poly(ferulic acid) (PFA) in which FA units are mainly linked together with C–C bonds. The colouration of PFA on fabrics occurs due to physical adsorption, and not because of interaction of covalent bond between PFA and fibres. The enzymatically dyed fabrics display yellow to orange colour hues, and pale to moderate colour depth, depending on fibre species and dyeing methods. The dyed fabrics show excellent rub fastness and staining fastness during washing, relatively weak light fastness and colour change fastness during washing; the two-step method shows better wash fastness ratings for colour change. The enzymatic dyeing of FA provides fabrics with multifunctional properties of antioxidant activity, UV-protection and deodorization.