Modification of cotton fabric with acrylamide in the presence of K2S2O8 for improving dyeability of natural dyes

Abstract

Cotton fabrics were modified using acrylamide as the aminating agent in the presence of potassium peroxodisulphate (K2S2O8) as a free radical polymerisation catalyst using a pad–dry–cure technique in order to improve the dyeability of cotton fabrics with natural dyes. Pre‐soaking of bleached cotton fabric with 5 g l−1 K2S2O8 and subsequent application of 10 g l−1 acrylamide monomer on the pre‐soaked cotton fabric, followed by drying of the padded fabric at 95°C for 5 min and curing of the dried fabric at 140°C for 5 min, produced most balanced improvements in dye uptake, tensile strength and wrinkle recovery angle for optimum retention of flexibility of the dyed substrates when pre‐treated cotton fabrics were dyed with Camellia sinensis and Punica granatum. Application of ferrous sulphate on pre‐treated cotton fabric following a pre‐salt application method and subsequently dyeing with Camellia sinensis and Punica granatum improved the depth of shade and all‐round colour fastness properties further. Infrared (IR) spectroscopy indicated that the treatment with acrylamide under the influence of K2S2O8 led to incorporation of poly(acrylamide) in cotton by the process of graft co‐polymerisation using the pad–dry–cure technique.