Bleaching Activators and the mechanism of bleaching activation

Abstract

Bleaching activators are compounds with O‐ or N‐bounded acetyl groups which are able to react with the strongly nucleophilic hydroperoxy anion to yield peroxyacetic acid. The peroxyacetic acid is decomposed in weakly basic media in a bimolecular reaction forming singlet oxygen. The maximum of the decomposition rate of peroxyacetic acid at pH = 8.3 is also the maximum of bleaching activity of systems containing both bleaching activators and sodium perborate; therefore singlet oxygen must play a decisive role in the activated bleaching of textiles during the washing process. Different bleaching activators can be compared both on the basis of their reaction rates with hydrogen peroxide in weakly basic media and on the basis of their reaction rates with piperidine in dioxane. A great number of potential bleaching activators was studied and compared.

Fluorescent Assay for Directed Evolution of Perhydrolases

“…6 In situ generation of peroxycarboxylic acids by hydrolysis of esters or amides in the presence of hydrogen peroxide is an alternative approach for producing active peroxycarboxylic acids when required in applications. 7 Peroxycarboxylic acid production employing hydrolases has been reported for proteases, 8,9 lipases, 10 and esterases, 11 which are mainly used in detergent formulations. In a patent application, 8 the reengineering of proteases for peroxycarboxylic acid production was reported for the first time.…”

Activated peroxide bleaching of regenerated bamboo fiber using a butyrolactam-based cationic bleach activator

“…This is plausible because hydrogen peroxide dissociates at pH 11 to 11.5 to release perhydroxyl anions that directly bleach fibers (Zeronian and Inglesby 1995). On the other hand, perhydroxyl anions react with bleach activators to generate peracid species, which can bleach fibers under milder conditions (Grime and Clauss 1990;James and Mackirdy 1990;Hofmann et al 1992;Beck et al 2007). However, in the case of regenerated bamboo fiber, TBBC failed to provide significantly enhanced bleaching efficiency under the conditions tested in the CCD.…”

“…Bleach activators are organic peracid precursors which liberate more kinetically active peracid in situ in the presence of hydrogen peroxide in a weakly alkaline aqueous solution (Grime and Clauss 1990;James and Mackirdy 1990;Hofmann et al 1992;Beck et al 2007). Using bleaching activators, a relatively benign bleaching system can be conducted at lower temperature and reduced time relative to conventional peroxide bleaching, thereby leading to reduced fiber damage.…”

Bleaching cellulosic fibers via pre-sorption of N-[4-(triethylammoniomethyl)-benzoyl]-butyrolactam chloride

“…Bleach activators are organic compounds that liberate peracids in the presence of hydrogen peroxide in alkaline aqueous solutions (Holst 1954;James and Mackirdy 1990;Hofmann et al 1992;Beck et al 2007). They are widely used in laundry detergent formulations (Grime and Clauss 1990), and are increasingly being considered for use in industrial textile bleaching in an attempt to reduce energy, processing time and fiber damage caused by conventional peroxide bleaching (Mathews 1999;Cai et al 2001;Wang and Washington 2002;Gursoy et al 2004a, b;Lim et al 2004Lim et al , 2005Cai and Evans 2007;Lavrič et al 2007).…”