DSC测定燃料电池质子交换膜中水的状态

发布时间：2018-06-29 09:35

本文选题：质子交换膜 + 自由水　；参考：《实验室研究与探索》2014年11期

【摘要】：为了探索燃料电池质子交换膜中水的存在状态及其对膜的质子传导性能的影响,以双酚A二缩水甘油醚型环氧树脂(DGEBA)为交联试剂,N,N-二甲基乙酰胺(DMAC)为溶剂,制备了磷酸化乙烯-乙烯醇的嵌段共聚物(EVOH)/DGEBA/多聚磷酸(PPA)的交联膜。介绍了用低温差示扫描量热法(DSC)测定该膜中自由水和结合水含量的方法,即通过DSC图谱总的吸热峰的积分面积得出总的焓变,由总的吸热峰在基线与切线间所夹右半部分的积分面积得出自由水的焓变,从而测得所制备的质子交换膜中的自由水和结合水含量。膜的离子交换容量(IEC)值及质子电导率分别采用酸碱滴定法及交流阻抗法测量。结果表明:随着膜在PPA中处理时间的增加,膜的吸水率、自由水的含量和键合水的含量都呈上升趋势,但自由水增长率大于键合水;膜的IEC值和质子电导率也随自由水含量的增加而增大;自由水含量的增加使膜的质子传导能力增强。
[Abstract]:In order to explore the existence of water in proton exchange membrane of fuel cell and its influence on proton conductivity, bisphenol A diglycidyl ether type epoxy resin (DGEBA) was used as crosslinking reagent, N- N- dimethyl acetamide (DMAC) was used as solvent, and bisphenol A diglycidyl ether type epoxy resin (DGEBA) was used as solvent. The cross-linking membrane of phosphorylated ethylene vinyl alcohol block copolymer (EVOH) / DGEBA / polyphosphoric acid (PPA) was prepared. The method of determining the free and bound water content in the film by low temperature differential scanning calorimetry (DSC) is introduced, that is, the total enthalpy change is obtained by the integral area of the total endothermic peak in the DSC spectrum. The enthalpy variation of free water is obtained from the integral area of the right half of the total endothermic peak between the baseline and the tangent line, and the free water and bound water contents in the prepared proton exchange membrane are measured. The ion exchange capacity (IEC) and proton conductivity of the membrane were measured by acid-base titration method and AC impedance method respectively. The results showed that with the increase of treatment time in PPA, the water absorption rate, free water content and bonded water content of the membrane showed an increasing trend, but the free water growth rate was higher than that of bonded water. The IEC value and proton conductivity of the membrane also increase with the increase of free water content, and the proton conductivity of the membrane increases with the increase of free water content.
【作者单位】：湖北大学材料科学与工程学院;湖北大学化学化工学院;
【基金】：深圳市功能高分子重点实验室开放研究课题深圳市功能高分子重点实验室经费资助
【分类号】：TM911.4

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