The sorption of a syntan on nylon and its resist effectiveness towards reactive dyes

The sorption behavior of a commercial syntan on nylon and its resist effectiveness towards the uptake of reactive dyes on both nylon and nylon/cotton blend fabrics were investigated. The sorption isotherms of the syntan on nylon at pH 4 fitted a dual sorption mechanism consisting of partition and Langmuir type models. Whereas Langmuir sorption saturation was little influenced by temperature in the range of 50–80 °C, partition coefficients and Langmuir affinity constants increased with increasing temperature, indicating that syntan sorption was endothermic. The ability of the syntan to resist the uptake of reactive dyes was greatly influenced by the nature of the dye and the temperature of syntan application; the observed increase in resist effectiveness that accompanied an increase in the temperature of syntan application can be attributed to a corresponding larger uptake of syntan and greater extent of diffusion of the syntan within the nylon substrate, together with a lower extent of syntan desorption during reactive dyeing.