过氧化氢对质子交换膜热降解和热稳定性的影响

Effect of H_2O_2 on Thermal Degradation and Stability of Proton-Exchange Membrane

研究了在80℃下3%过氧化氢水溶液对质子交换膜氧化作用后的热稳定性及热降解动力学。利用热重分析在氮气气氛、升温速率分别为5℃/min、10℃/min和20℃/min条件下,采用Kissinger、Flynn-Wall-Ozawa、Friedman和Modi-fiedCoats-Redfem方法对膜氧化后的非等温动力学数据进行了分析。TG-DTG曲线显示氧化后质子交换膜分解率达到5%时,最低热降解温度为287.8℃,热分解过程经历两个阶段,第一和第二阶段热分解区间分别在300℃～404℃和374℃～586℃。采用不同方法的计算结果显示第一阶段的平均表观活化能约为177.5kJ/mol,第二阶段的平均表观活化能约为242.4kJ/mol。

The thermal stability and thermal degradation kinetics of proton-exchange membrane were investigated,as it was oxidized and attacked by 3% aq.H2O2 solution in 80 ℃. Non-isothermal kinetic data of oxidized membrane was analyzed by using Kissinger,Flynn-Wall-Ozawa,Friedman and modified Coats-Redfern methods and the thermogravimetry analysis ,under the conditions of nitrogen atomosphere and heating rate of 5 ℃/min,10 ℃/min and 20 ℃/min. TG-DTG curves show that the minimum temperature of the thermal degradation is greater than 287.8 ℃,when the membrane is oxidized and the decomposition rate reaches 5%. The proton exchange membrane shows two stages of thermal degradation.Thermal decomposition ranges in first and second stage is among 300 ℃～404 ℃ and 374 ℃～586 ℃ respectively. The results calculated by various methods indicate that the average value of apparent activation energy in first stage is about 177.5 kJ/mol,and the average value of apparent activation energy in second stage is about 242.4 kJ/mol.