高效液相色谱研究丝素亲核基团与一氯均三嗪型活性染料反应动力学

Reaction Kinetics of Monochlorotriazine Reactive Dyes with Neucleophilic Groups in Silk by High Performance Liquid Chromatography

以异丙胺、对甲酚和甲醇分别模拟蚕丝丝素的氨基、酚羟基和醇羟基,应用高效液相色谱分析一氯均三嗪型活性染料与蚕丝丝素的不同亲核基团的反应速率。结果表明:在pH=8～10、70～95℃的条件下,染料的酚解总反应速率远大于染料的氨解总反应速率和醇解总反应速率。其中C.I.活性红24和C.I.活性橙2在pH=9,95℃条件下的酚解总速率分别约为其氨解总反应速率的8.5倍和12.5倍,为其醇解总反应速率的23倍和50倍;该两染料的酚解效率分别为47.4和96.3,氨解效率分别为4.6和6.9,醇解效率仅为1左右。通过异丙胺-对甲酚-甲醇混合溶液(1∶10∶100,V/V)模拟蚕丝与染料的反应,研究一氯均三嗪型活性染料与丝素上亲核基团的反应选择性,推断出一氯均三嗪型活性染料染蚕丝的最适宜条件为pH=8～9,温度85℃左右。在此条件下,酚羟基在蚕丝的一氯均三嗪型活性染料染色中起主要作用,氨基起次要作用,而醇羟基的作用甚微。

Using Isopropyl amine （0. 003 mol/L）, p-methyl-phenol （0.03 mol/L） and methanol （ 1 mol/L） for simulating amino groups, phenol groups and hydroxyl groups in silk fibroin respectively, the reaction rate of different nucleophilic groups in silk with monochlorotriazine reactive dye was studied at various temperature and pH by high performance liquid chromatography. It was found that the overall reaction rate of dyes＇ phenolysis was by far higher than that of ammonolysis and alcoholysis on the conditions of 70 - 95℃ and pH = 8 - 10. The phenolysis overall reaction rates of C. I. reactive red 24 and C. I. reactive orange 2 were 8.5 and 12.5 times of their ammonolysis＇, and 23 and 50 times of their alcoholysis＇ in the term of pH 9 and 95℃. The phenolysis efficiencies of those two dyes were 47.4 and 96.3, the ammonolysis efficiencies were 4.6 and 6.9, and the aleoholysis efficiencies were only 1. Using a mixture （1：10： 100, v/v） of isopropyl amine, p-methyl-phenol and methanol to simulate the silk fibroin, the reaction selectivity between the monochlorotriazine reactive dyes and nucleophilic groups in silk fibroin was investigated. It was deduced that monochlorotriazine reactive dyes are suitable for dyeing silk on the conditions of about 85℃ and pH = 8 - 9, and under this condition, phenol groups are the major groups in silk dyeing with monochlorotriazine reactive dyes, amino groups are the minor groups, and the contributions of hydroxyl groups can be neglected.