Latest Progresses in Wrinkle-Resistant Finishing of Cotton Fabrics: Citric Acid Crosslinking and Follow-up H_2O_2/UV Bleaching

摘要

Citric acid (CA) is a natural polycarboxylic acid and also can effectively crosslink cellulose, providing wrinkle-resistant functions to cotton fabrics. Formation of unsaturated aconitic acid isomers and other acids under elevated temperatures causes a yellowing appearance on the crosslinked cotton products, inhibiting its applications. While bleaching is another common finish of cotton fabrics, hydrogen peroxide (H202) bleaching under alkaline condition could improve whiteness of the CA-crosslinked fabrics but sacrificing certain crosslinking perfonnance of the products due to alkaline hydrolysis of ester connections. Hydrogen peroxide could generate hydroxyl radicals under ultraviolet irradiation (H202/UV) and can degrade most unsaturated structures, which was employed in treatment of CA-crosslinked fabrics under a neutral condition. The treated fabrics presented desired wrinkle recovery angles, idea whiteness, and proper tensile strength retention.