聚砜基氢氧根离子交换膜制备及性能

发布时间：2018-05-06 13:27

  本文选题：聚砜 + 氢氧根离子交换膜　； 参考：《大连理工大学》2015年硕士论文

【摘要】：阴离子交换膜是氢氧燃料电池的核心部件,研发高离子传导率、优良化学、机械性能的高性能阴离子交换膜成为现阶段氢氧燃料电池研究的重点。现有研究思路主要集中在设计聚合物主链及碱性功能基团侧链两个方面,如功能化单体聚合形成嵌段聚合物以及强碱性、稳定性好的碱性功能基团的改性研究。本文以性能优良的热塑性工程塑料聚砜为主链,提出三甲胺均相季铵化,以及乌洛托品、K支链醚键咪唑作为新型碱性功能基团的方法,制备性能优良的聚砜基阴离子交换膜。针对非均相法制备的阴离子交换膜反应不均匀、离子传导率不高的问题,开发混合溶剂,实现氯甲基化聚砜与三甲胺的均相季铵化反应,成功制备了一系列三甲胺聚砜阴离子交换膜。均相法和非均相法制备的膜,离子交换容量分别可达到0.52-1.13 mmolg-1和0.56-1.28 mmolg-1与非均相膜相比,均相季铵化膜中季铵基团更多(离子交换容量,IEC约增加10%),膜的含水量约提高8.8%,氢氧根传导率的提高程度远大于离子交换容量和含水量的提高程度,常温下离子传导率最大可提高29.3%,透射电镜(TEM)显示均相法制备的膜具有更好的微观相分离结构。尽管均相法制备聚砜膜电导率有一定程度提高,但没能解决提高季铵基团数量造成过度溶胀和高温强碱下降解问题。针对上述问题,选用含有四个氮、金刚烷结构的乌洛托品作为新的季铵化试剂,成功合成乌洛托品季铵化聚砜阴离子交换膜(CPSF-QuOH),通过核磁共振确定了季铵化程度及交联度。CPSF-QuOH膜的离子交换容量从1.39-2.23mmol g-1,交联度在15-26%,水吸收率和溶胀度分别保持在30%和20%以下,30℃时离子传导率从18.2 mS cm"1增大到40mS cm-1,表明CPSF-QuOH膜具有较高的氢氧根离子传导率和良好的机械稳定性。CPSF-QuOH膜初始分解温度高达204℃,具有良好的热稳定性；60℃下1MKOH强碱溶液中浸泡7天,离子传导率衰减很小(最大衰减14.4%),测试证明具有很好的化学稳定性。为进一步提高阴离子交换膜的稳定性,首先合成氯化1-(2-羟乙基)-3-甲基咪唑摀盐为季铵化试剂,然后通过威廉姆森成醚反应,成功合成了醚键接枝咪唑筠化聚砜(EPSF-ImCl),进而浇铸成膜,制备了理论IEC为1.37-1.95mmolg-1的EPSF-ImOH膜。20℃时,EPSF-ImOH 1.22(理论IEC为1.95mmol g-1)的氢氧根离子传导率达到27.4 mScm-’,60℃时升高到72mScm-1。EPSF-ImOH膜初始分解温度169℃,高于三甲铵基团的热初始分解温度120℃,表明具有良好的热稳定性；80℃下1MKOH强碱溶液中浸泡144h,离子传导率仅衰减1.2%,测试证明具有很好的化学稳定性。
[Abstract]:Anion exchange membrane is the core component of hydrogen oxygen fuel cell. The research and development of high ionic conductivity, excellent chemical and mechanical properties of high performance anion exchange membrane has become the focus of research on hydrogen oxygen fuel cell. The existing research ideas mainly focus on the design of polymer main chain and basic functional group side chain, such as functionalized monomer polymerization to form block polymer and strong alkaline, good stability of basic functional groups modification. In this paper, using thermoplastic engineering plastics polysulfone as main chain, trimethylamine homogeneous quaternization and Ulotropine K branched chain ether imidazole as new basic functional groups were proposed to prepare polysulfone based anion exchange membranes with excellent properties. Aiming at the problems of heterogeneous anion exchange membrane reaction and low ion conductivity, a mixed solvent was developed to realize the homogeneous quaternary ammonium reaction of chloromethylated polysulfone with trimethylamine. A series of trimethylamine polysulfone anion exchange membranes were successfully prepared. The ion exchange capacities of the membranes prepared by homogeneous and heterogeneous methods are 0.52-1.13 mmolg-1 and 0.56-1.28 mmolg-1, respectively. In homogeneous quaternary ammonium film, there were more quaternary ammonium groups (ion exchange capacity increased by about 10%, water content of membrane increased about 8.8%, the increase of hydrogen oxygen conduction rate was much greater than that of ion exchange capacity and water content. The maximum ionic conductivity can be increased by 29.3% at room temperature. Transmission electron microscopy (TEM) shows that the membrane prepared by homogeneous phase method has a better microstructure. Although the conductivity of polysulfone membrane prepared by homogeneous method has been improved to some extent, it has not solved the problem of excessive swelling and degradation under high temperature and strong alkali caused by increasing the number of quaternary ammonium groups. To solve the above problems, Ulotropine with four nitrogen and adamantane structures was selected as a new quaternary ammonium reagent. Urotropine quaternary ammonium polysulfone anion exchange membrane (CPSF-QuOHH) was successfully synthesized. The degree of quaternary ammonium conversion and crosslinking degree. CPSF-QuOH membrane ion exchange capacity was determined from 1.39-2.23mmol g-1, crosslinking degree was 15-26%, water absorptivity and swelling degree were kept at 30% and 30%, respectively. The ionic conductivity increases from 18.2mScm "1 to 40mS cm-1 at 30 鈩，

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