Preparation And Mechanism Study Of Bleaching Catalyst Used For Fabric Low-temperature Oxygenated Washing

Bleaching process is very important for the human daily life and industrial applications.Peroxide bleaching agents have been used for many years in fabric and hard surface bleaching.But this bleaching agent is inefficient at low temperature,in order to solve this problem,bleaching activators and catalysts were introduced into the system.And based on the drawbacks of current activators and catalysts,such as low activity in low temperature and serious fabric damage,we reported two different catalysts for laundry bleaching,one is a complex based on lanthanide metals,and the other is a metal-free organic compound.Firstly,a new complex was prepared by complexation of cerium chloride with Tiron,a water-soluble catechol ligand.It was found that the bleaching efficiency and the destruction of cotton fabric strength were equivalent to tetraacetyldiamine(TAED),and the dosage was less.In addition,a class of heterocyclic compound 1,4,7-trimethyl-1,4,7-triazonane(TMTACN)was found to have considerable catalytic activity of bleaching without complexation with metal ions.The influence of the catalyst dosage,SPC dosage,stain type,bleaching time and so on on the bleaching results was investigated and the catalyst was also applied in the automatic dishwasher.The destructive degree to the cotton fabric during bleaching was also studied,the results showed that the destructive degree to the cotton fabric was greatly reduced compared with the manganese complex.The mechanism of its bleaching process and reactive intermediate was further studied,and it was found that TMTACN,as a precursor,complexed with metal ions in bleaching liquor to form a new complex and play a synergistic catalytic role.