Dyeing of polyamide fabrics with a reverse micellar system using soybean oil as a solvent

The current study reports the results of non-aqueous dyeing on polyamide fabrics based on a reverse micellar system composed of a stable emulsion of soybean oil, a co-surfactant, a nonionic surfactant and acid dyes. The system does not make use of water or electrolytes and significantly reduces the dyebath volume. The influence of the hydrophilic lipophilic balance of the surfactants was evaluated, and it was found that the more hydrophilic the surfactant, the better the interaction of the reverse micellar emulsion with the substrate and, consequently, the greater the resulting colour strength. The co-surfactant plays an important role in the system, as its proportion to the surfactant/oil mixture is directly related to better exhaustion of the dyebath. The results were compared with those from a conventional water-based dyeing system. Colour matching was performed using the CIELab colour difference formula (ΔE) measured by a reflectance spectrophotometer.