Investigation of dyeing properties of polyetherimide fibers

In this thesis study, the coloring properties of polyetherimide (PEI) fibers, one of the heat-resistant high-performance fiber types, were investigated in detail. The first study conducted within the scope of the thesis focused on the dyeing processes of PEI fiber fabrics with disperse dyestuffs. After dyeing according to the Orthogonal Array (Taguchi experimental design method), the color strength, strength and fastness measurements of the samples were statistically analyzed and the ideal dyeing conditions were determined. Another topic covered within the scope of the thesis is the reduction clearing processes applied after the disperse dyeing of PEI fibrous structures. The color fastness and strength of PEI fiber fabrics were evaluated after reduction clearing processes carried out with commonly used reduction clearing agents at different temperatures, durations, and alkaline/acid conditions. In addition, the environmental burden of wastewater from these reduction clearing processes was analyzed, and the most effective reduction clearing procedures were determined by calculating the carbon footprint of the processes. The third and final topic of the thesis focuses on the development of environmentally friendly dyeing methods for PEI fiber structures. In this context, the usability of natural alternatives to carrier agents—among the most hazardous textile auxiliaries in the industry and frequently used in dyeing hydrophobic textile fibers such as high-performance fibers—was investigated. Turmeric was used as a natural dye and various essential oils were used as natural carriers. Short-term dyeing processes were carried out in a microwave environment. The results show that PEI fibers can be easily colored with turmeric in a microwave environment and that essential oils such as vanilla oil, lavender oil, and sage oil can be effectively used as natural carrier agents in the dyeing processes of PEI fibers with turmeric. In conclusion, this thesis study aims to determine the effective and efficient conditions for the coloring processes of PEI fibers, making significant contributions to the development of sustainable and environmentally friendly dyeing processes in the textile industry.