The beetroot peels can be a sustainable source of betalains that can dye the wool materials through green processes based on low water and energy consumption. Green chemistry in the extraction of betalains from colored food waste/peels from red beetroot involved the use of water as a solvent, without other additives. In order for the extract obtained to be able to dye the wool, it was necessary to functionalize betalains or even the wool. Three types of sustainable functionalizations were performed, with (1) acetic acid; (2) ethanol; and (3) arginine. For each functionalization, the mechanism that can justify dyeing the wool in intense colors was elucidated. The characterization of the extract was performed with the data provided by UV-VIS and HPLC-MS analyses. The characterization of the wool dyed with the extract obtained from the red beetroot peels was possible due to the information resulting from the FTIR and CIELab analyses. The functionalizations of betalains and wool in acid environments lead to the most intense red colors. The color varies depending on the pH and the concentration of betalains.

This study may open a new way to obtain the coloration of a polymer during functionalization. Two polyacrylonitrile (PAN) polymers in the form of textile fibers (Melana and Dralon L) were subjected to functionalization treatments in order to improve the dyeing capacity. The functionalizations determined by an organo-hypervalent iodine reagent developed in situ led to fiber coloration without using dyes. KIO₃ was formed in situ from the interaction of aqueous solutions of 3–9% KOH with 3–9% I₂, at 120 °C. The yellow-orange coloration appeared as a result of the transformations in the chemical structure of each functionalized polymer, with the formation of iodinehydrin groups. The degree of functionalization directly influenced the obtained color. The results of the Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Map and Temogravimetric Analysis (TG) plus Differential Thermal (DTA) analyses indicated the presence of new functional groups, such as iodine-oxime. The X-ray diffraction (XRD) analysis confirmed the change of the crystalline/amorphous ratio in favor of the former. The new groups introduced by functionalization make it possible to dye with classes of dyes specific to these groups, but not specific to PAN fibers, thus improving their dyeing capacity.

This study investigates the influence of conventional textile pretreatment and periodate oxidation parameters on the structural modifications and functional properties of woven cotton fabrics. Unlike most studies focused on cellulose pulps or isolated textile fibers, the present work examines how the initial structural state of the textile substrate, determined by its pretreatment history, governs the oxidation pathways. Cotton fabrics were subjected to alkaline scouring (SC), hydrogen peroxide bleaching (BC), and combined scouring–bleaching (SBC), followed by sodium periodate oxidation under controlled conditions. Carbonyl species were quantified analytically and identified by ATR-FTIR spectroscopy, while structural changes were evaluated by X-ray diffraction (XRD). Mechanical properties were assessed using the normalized parameters (Fa/Fa₀ and E/E₀), hydrophilicity by water absorption capacity (WAC), and optical stability by the yellowness index (YI). The results demonstrated that the pretreatments influence the oxidant accessibility and the balance between carbonyl speciation. XRD analysis shows a moderate decrease in crystallinity, indicating partial preservation of the crystalline domains, whereas mechanical properties decrease significantly (35–65%), concomitant with a 25–45% reduction in WAC. These results suggest that the impairment in mechanical and hydrophilic properties is primarily governed by localized C2–C3 bond scission, secondary oxidative reactions, and supramolecular rearrangements, rather than by bulk crystalline loss. The oxidized SC series exhibits higher YI values associated with an increased free aldehyde content, while the BC and SBC fabrics show improved optical stability. Overall, these results demonstrate that pretreatment history governs periodate oxidation pathways and establishes clear structure–property relationship relevant for the controlled functionalization of woven cotton fabrics.