Facile synthesis of a novel, highly effective, more sustainable and cost-effective cationic bleach activator for cotton: N-[4-(N,N,N)-triethylammoniumchloride-butyryl] caprolactam

Abstract: Compared to conventional peroxide bleaching, using a bleach activator in a peroxide bleaching bath is an effective and kinetically more potent oxidation generating highly reactive peracid in situ, providing low-temperature bleaching with shorter dwelling time. In the presence of an activator, bleaching can be achieved at lower temperatures and reduced time relative to the conventional peroxide bleaching, resulting in decrease in energy consumption and reduced fabric damage. Cationic bleach activators were investigated as the next generation bleach activators that exhibit inherent substantivity towards cellulosic fibers. In this study, facile synthesis of a more sustainable and cost-effective bleach activator, based on an aliphatic acyl chloride (4-chlorobutyryl chloride), was reported: Compared to aromatic-based bleach activator, it showed comparable bleaching results at lower temperature. Fourier transform infrared and high resolution mass spectrometry confirmed the molecular structure of the named activator: N-[4-(N,N,N)-triethylammoniumchloride-butyryl] caprolactam, TBUCC. Bleaching performance of TBUCC was evaluated in terms of whiteness index, water absorbency and fiber damage and compared with conventional peroxide system. Results revealed that our developed TBUCC-activated bleaching system provided comparable whiteness index, water absorbency with a higher degree of polymerization at significantly lower temperature (70 °C) as compared to conventional peroxide bleaching. Graphical abstract: [Figure not available: see fulltext.]