Synthesis Of Manganese Complex Of Briding Macrocyclic Polyamine And Analysis Of Its Catalytic Activity In Low Temperature Bleaching Cotton Fabric Using H₂O₂ As Oxidant

With the development of dyeing and finishing industry, the contradiction of bleaching agents with energy saving, consumption reduction and environmental protection is increasingly prominent. The conventional oxidation bleaching agents have some defects such as high energy consumption, sensitively injured fiber strength, rough fabric to touch, and Enormous environmental pollution. Hydrogen peroxide has been widely applied in bleaching procedures of all kinds of textile fabrics because of high whiteness of textiles and little environmental pollution.Presently there are many drawbacks of hydrogen peroxide activation agent in dyeing and finishing industry, like more hydrogen peroxide doses when bleaching in low temperature, high bleaching costs, difficult to assist with other promoters. Application of imitating enzyme namely mimic enzyme functional similar to biological enzyme in bleaching is an efficient method to overcome these disadvantages.The mimic enzyme systems used in bleaching include metal porphyrin complexes and non metal porphyrin complexes. Metal porphyrin complexes involve iron porphyrin and manganese porphyrin, and non metal porphyrin complexes involve metal phthalocyanine, GIF system, schiff base, copper amine complex and dinuclear metal complex. The macrocyclic polyamine catalyst has strong activity and this paper will investigate its synthesis and application properties.The promoter of macrocyclic polyamine 1,2-bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-y) ethane and its manganese complex [LMn(Ⅲ) (μ-O)2(μ-OAc) Mn(Ⅳ)](CH3COO)2 are synthesized through five step method in this paper, and the manganese complex is analyzed confirmed by UV-visible spectra analysis, thermal gravimetric analysis, ultraviolet spectroscopy and infrared spectroscopy analysis.Manganese complex of macrocyclic polyamine 1,2-bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-y)ethane as catalyst for H2O2 was used in low temperature bleaching of cotton fabric. The influence of concentrations of complex and H2O2, temperature, pH and treating time on bleaching properties was discussed in detail. The optimal processing conditions were listed as follows:30%H2O2 10g/L, complex 30μmol/L, penetrating agent lg/L, stabilizer 1g/L, pH=12.5, liquor to goods ratio of 20:1, and the fabrics were bleached at 80℃for 60 min. The treated fabric achieves the whiteness index of 68.94% and bursting strength retention was 85.93%.