Environmental modification of cellulose fibers for reducing dye diffusion rate by anionic polyacrylamide

Reactive dyeing is the primary method for coloring cellulose fibers due to its vibrant colors, various hues, excellent colorfastness, and cost-effectiveness. However, this process consumes a large amount of water and chemicals, leading to significant environmental concerns due to the wastewater. Non-aqueous media/less water dyeing has emerged as a cleaner alternative, showing promising results in dyeing cotton fibers with reactive dyes. Nevertheless, the rapid adsorption rate of dyes can impact the evenness of dyeing. This study explores the use of anionic polyacrylamide (APAM) in the modification bath to reduce dye adsorption rate and enhance dye desorption during cellulose fibers dyeing. Fourier transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscope (FSEM) analysis revealed effective interaction between APAM and cellulose fibers. Thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and breaking strength tests indicated minimal impact on the thermal stability and physical properties of cellulose fibers with APAM modification. Zeta potential testing demonstrated that APAM modification reduced the surface potential of cellulose fibers and increased their negative charge. The adsorption rate of reactive dye decreased with APAM modification, while dye fixation, washing, and rubbing fastness remained largely unaffected. Adsorption isotherm results supported the weakening of the affinity between dyes and fibers after APAM treatment. Furthermore, the electrostatic potentials of fibers decreased after APAM modification. Compared to salt-free dyeing in non-aqueous media dyeing systems, anionic polymer modification not only improves the level dyeing performance of cotton fiber and reduces 0.9 % in dyeing costs, but also increases production efficiency.