Synthesis of metal complex and its application in low temperature bleaching

Binuclear manganese complex[(Me3TACN)2Mn2(μ-O)(μ-CH3CO2)2] 2·1H2O(MnAcL) and iron complex[(Me3TACN)2Fe2(μ-O)(μ-CH3CO2)2] 2·1H2O(FeAcL) of 1,4,7-trimethyl-1,4,7-triazacyclononane containing carboxylic bridge were synthesized and characterized by FT-IR,elemental analysis(EA) and TGA,and their structures were confirmed.Low temperature bleaching of knitted cotton fabrics was performed using MnAcL and FeAcL as the catalyst for H2O2 and effects of temperature,complex concentration,H2O2 mass concentration,and pH on the bleaching results were investigated,and the optimized process conditions were determined as follows: 30% H2O2 10 g/L,complex MnAcL 10 μmol/L(FeAcL 15 μmol/L),penetrating agent 1 g/L,stabilizer DTA 1 g/L,pH=10,bleaching at 70 ℃ for 60 min.The whiteness index and bursting strength retention of fabrics treated with MnAcL and FeAcL were 82.3% and 65.7%,and 95.5% and 96.9%,respectively.The fabric bleached with MnAcL at low temperature exhibited similar whiteness and wettability to the fabric bleached with the conventional high temperature bleaching technique,but showed higher bursting strength retention.