Enzymatic coloration of polyamide fabrics and its comparison with conventional dyeing

Among the textile wet processes, the colouring process is the process step that causes the most environmental pollution. New approaches that support sustainable production instead of environmentally harmful processes are extensively researched in the literature. When considering substitution of chemical processes with environmentally friendly methods, one of the issues that comes to mind is enzymatic processes. It is noteworthy that in recent years, interesting and promising studies on the use of laccase enzymes in textile dyeing have been published in the literature. However, studies on enzymatic colouring are still very limited and sufficient success has not been achieved especially on polyamide. The aim of this study is to develop an environmentally friendly enzymatic dyeing method, which can be an alternative to dyeing polyamide knitted fabrics with 1:2 metal complex dyes according to the exhaustion method. For this purpose, various phenol and amine compounds, and their mixtures were used as precursor, and the colours that can be obtained by enzymatic colouring have been determined. In addition, optimisation of enzymatic colouring conditions (enzyme concentration, temperature and time) was carried out for the precursors that gave the best results in terms of colour and fastness. Furthermore, enzymatic dyeing was compared with conventional 1:2 metal complex dyeing in terms of technical and economic aspects. The reaction pathways in enzymatic coloration with laccase enzyme by using various precursors were also explained by Fourier-transform infrared (FTIR) analysis.