TEMPO氧化体系氧化棉纤维的动力学研究

研究了2,2,6,6-四甲基哌啶氧化物自由基(TEMPO)/NaClO/NaBr氧化体系氧化棉纤维的动力学。结果表明,TEMPO/NaClO/NaBr氧化体系对棉纤维的氧化可用基于纤维素特殊结构的两个一级反应动力学来描述:即无定形区和结晶区的动力学过程。在所用的TEMPO浓度范围内,氧化反应速率与TEMPO的浓度成正比。在较低浓度时,氧化反应速率与NaBr用量也成正比,但NaBr浓度超过1.0 mmol/g时,氧化反应速率不随NaBr浓度增大而增大。温度对氧化反应速率常数的影响可以用Arrhenius方程来描述,并由Arrhenius方程求得棉纤维的表观活化能为56.66 kJ/mol。

Study on oxidation kinetic of cotton fibers oxidation with TEMPO

The oxidation kinetics of the cotton fibers with TEMPO was investigated.The results showed that the oxidation reaction of the cotton fibers by TEMPO/NaClO/NaBr system could be approximately described in two pseudo-first-order reaction kinetics based on the special cellulose structure,namely the dynamics of amorphous and crystall regions.In the concentration range used,the rate constant k was directly proportional to the concentration of TEMPO.As to NaBr,the rate constant was proportional to the concentration in a relatively lower range,but oxidation reaction rate did not increase with concentration of NaBr when its concentration was above 1.0 mmol/g.The effect of temperature on the rate constant could be well described by Arrhenius equation,the apparent activation energy measured was about 56.66 kJ/mol.