An eco-friendly way to whiten yellowish anti-wrinkle cotton fabrics using TBCC-activated peroxide low-temperature post-bleaching

Abstract

Anti-wrinkle finished fabrics have the problem of yellowing, especially the citric acid-treated fabrics. Post-bleaching using hydrogen peroxide (H2O2) could endow better whiteness to yellowish fabrics, however during the process some anti-wrinkle properties are lost. The crosslinking bonds of anti-wrinkle fabrics would be broken under high temperature and strongly alkaline conditions of H2O2 post-bleaching. In this work, an N-[4-(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC)-activated peroxide post-bleaching method is developed, which has milder conditions and can better bleach the yellowish anti-wrinkle fabrics. The proposed method hardly breaks any crosslinking bond. Moreover, a one-time post-bleaching method for whitening anti-wrinkle fabrics is proposed, which means that fabrics would not be bleached before finishing, rather are bleached only once after the finishing. In this regard, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy are employed to provide key evidence for changes before and after the post-bleaching process. Whiteness, wrinkle recovery angles, tensile strength retention, wettability and level of durable press of cotton fabrics before and after the post-bleaching treatment are evaluated. The results reveal that one-time TBCC-activated peroxide post-bleaching can effectively whiten the yellowish fabric and maintain a good anti-wrinkle property. This study would be helpful in establishing an eco-friendly way to produce high-quality anti-wrinkle cotton fabrics.