Low-temperature bleaching of cotton fabric using a copper-based catalyst for hydrogen peroxide

摘要

Hydrogen peroxide can be catalysed to bleach cotton fibres at a temperature of 70 ℃ by incorporating the copper-based catalyst [Cu(TPMA)Cl]ClO_4·1/2H_2O in the bleaching solution. The effects of pH, temperature, and concentration of catalyst and hydrogen peroxide on bleaching effectiveness were evaluated. The effects of other transition metal complexes of tris(2-pyridylmethyl)amine were also examined. The bleaching mechanism was investigated by studying the active species. The results showed that a satisfactory whiteness index could be obtained at low temperature with the copper-based catalyst, and it also had a competitive advantage in protecting cellulose from severe chemical damage. Cu(Ⅰ)TPMA(OOH)~- was the active species in bleaching.