The stability of monochlorotriazinyl reactive dyes on cellulose films in aqueous alkaline solutions containing peroxide bleaching agents

The stability of seven reactive (one difluoromonochloropyrimidinyl and six monochlorotriazinyl) dyes on cellulose immersed in sodium peroxoborate (PB) solution (UK-TO solution) containing tetraacetylethylenediamine (TAED) was examined using cellulosic films at 60 degreesC. The extent of dye loss tha t occurred from the dyed cellulosic films which were immersed in the UK-TO solution without detergent correlated closely to the ratings obtained using the BS 1006 UK-TO wash test. The dye loss that occurred from the dyed cell ophane films was attributed to three contributions, namely, alkaline hydrol ysis of dye-fibre bonds, oxidative fading of the dye chromophore by peroxid es and cellulose degradation accelerated by PB and TAED. The alkaline hydro lysis of the dye-fibre bond and the extent of cellulose degradation in the UK-TO solution were the main contributions to the dye loss; dye oxidation w as a minor factor in the dye loss mechanism. The physical, bonding of the d ye molecules reinforced the covalent dye-fibre bond stability towards the U K-TO solution. (C) 2001 Elsevier Science Ltd. All rights reserved.