Formaldehyde-Free Wrinkle Resistant Treatment of Cotton Fabrics with Novel Aromatic Polycarboxylic Acids

Cotton always has a large share in the textiles and clothing market. Cotton apparel is soft and easy-care but it can cause wrinkles easily. Formaldehyde derivatives have been used for addressing cotton fabrics wrinkle problem for years but health concerns limit their applications. A novel approach to formaldehyde-free wrinkle-free cotton fabric was investigated. Aromatic acids were considered as effective crosslinking agents. Aqueous solutions of 1,2,4-benzenetricarboxylic anhydride (BNTCAN) were used in treatment of cotton fabrics to change their wrinkle property. Different factors, such as concentrations, catalysts, temperature, pH, and wetting agents, were studied. Tensile strength was tested to check the damage level of the treated fabrics. Wrinkle recovery angles (WRA) of the cotton fabrics were tested to evaluate their wrinkle resistant performance. A reaction mechanism between cotton fabrics and BNTCAN was proposed. Results showed that BNTCAN was hydrolyzed into acid first, and the acid directly reacted with hydroxyl groups on cellulose to form ester bonds. This direct esterification reaction theory was supported by thermal and infrared analyses. Another two aromatic chemicals, 4,4'-oxydiphthalic anhydride (ODPA) and ethylene glycol bis(4-trimellitate anhydride) (EGBTA) were investigated. Since the structures are longer and more flexible, compared with BNTCAN, crosslinking efficiency and WRA of treated cotton fabrics were improved.