高性能磺化聚酰亚胺质子交换膜材料的制备与性能研究

发布时间：2018-01-28 08:00

本文关键词： 燃料电池质子交换膜磺化聚酰亚胺化学稳定性　出处：《深圳大学》2017年硕士论文　论文类型：学位论文

【摘要】：质子交换膜燃料电池(PEMFC)可以直接将燃料的化学能转变为电能,是一种高效清洁的能源装置,被认为是具有革命意义的新一代能源动力系统。PEMFC的核心部件是质子交换膜(PEM),其各项性能将直接影响燃料电池的总体性能,开发低成本、高性能的质子交换膜对PEMFC的发展和广泛应用具有重要意义。磺化聚酰亚胺(SPIs)凭借其卓越的热稳定性、机械性能和燃料阻隔率,成为一种非常有发展前景的质子交换膜材料。然而,酰亚胺环的化学稳定性在燃料电池运行环境中并不理想,提升磺化聚酰亚胺质子交换膜的化学稳定性是该研究领域的热点。近年来,多种增强SPI化学稳定性的方法被报导,如改变化学结构、将膜进行交联,但这些方法在实际应用时仍存在一些问题,需进一步的改进。在本课题组近期的研究中发现,高支化结构可以有效的提升磺化聚合物质子交换膜的化学稳定性,而且可以在一定程度上增加膜材料的电导率。本论文在课题组近期研究成果的指导下,针对磺化聚酰亚胺质子交换膜发展中存在的问题,制备了多种磺化聚酰亚胺质子交换膜,并对它们的各项性能进行了研究,具体研究内容与结果如下:1)以商业化的单体为原料,制备了四类不同结构、不同支化度的磺化聚酰亚胺质子交换膜,研究了非磺化二氨单体和支化结构对质子交换膜的各项性能的影响。结果表明,支化结构的引入可以增强膜的氧化稳定,增强程度与聚酰亚胺本身的化学结构有关;在刚性较强的主链结构中,引入支化结构对膜的电导率有明显提升;但支化结构的引入对膜的机械性能是不利的。2)针对支化磺化聚酰亚胺质子交换膜机械性能下降的问题,本论文又设计制备出含支化结构的交联磺化聚酰亚胺质子交换膜。通过在主链引入高支化结构可以弥补交联型磺化聚酰亚胺质子交换膜电学性能差的问题,并进一步增强膜的化学稳定性,还同时使膜材料具备优秀的机械性能。更重要的是,在电池测试中,这种膜材料展示出优异的功率密度,其功率密度最高值比直接交联型膜提高了24%。本工作将为制备高电学性能交联型质子交换膜材料提出一种新的思路。3)交联型磺化聚酰亚胺不能溶解,给成型加工造成困难,针对这一问题,本论文又设计并合成了一种侧链含有甲氧基硅烷的磺化聚酰亚胺,制备成薄膜后,膜可溶解并可多次溶解并重复制备薄膜;并最终在酸化时同时发生交联反应。结果表明,使用这种方式制备的薄膜,其化学稳定性大幅提高且电导率下降较低,同时其甲醇阻隔率也有明显提升。在直接甲醇燃料电池测试中,用这种方法制备的薄膜功率密度仅少量下降,且远高于商业化Nafion 212膜。
[Abstract]:Proton exchange membrane fuel cell (PEMFC) can directly convert the chemical energy of fuel into electric energy. It is an efficient and clean energy device. The core component of PEMFC, which is considered to be a new generation of energy power system with revolutionary significance, is the proton exchange membrane (PEMN). The performance of PEMFC will directly affect the overall performance of fuel cells and the development of low cost. High performance proton exchange membranes are of great significance for the development and wide application of PEMFC. Sulfonated polyimide (PEMFC) has excellent thermal stability, mechanical properties and fuel barrier rate. As a promising proton exchange membrane material, however, the chemical stability of imide ring is not ideal in the fuel cell environment. Improving the chemical stability of sulfonated polyimide proton exchange membranes is a hot topic in this field. In recent years, many methods to enhance the chemical stability of SPI have been reported, such as changing the chemical structure and cross-linking the membranes. However, there are still some problems in the practical application of these methods, which need to be further improved. In our recent research, it is found that the high branching structure can effectively improve the chemical stability of sulfonated polymer proton exchange membrane. Furthermore, the conductivity of membrane materials can be increased to some extent. Under the guidance of the recent research results of our research group, this paper aims at the problems existing in the development of sulfonated polyimide proton exchange membrane. A variety of sulfonated polyimide proton exchange membranes were prepared and their properties were studied. The specific contents and results are as follows: 1) four kinds of different structures were prepared using commercial monomers as raw materials. The effects of non-sulfonated diammonium monomers and branched structures on the properties of sulfonated polyimide proton exchange membranes with different branching degrees were studied. The addition of branched structure can enhance the oxidation stability of the film, and the enhancement degree is related to the chemical structure of the polyimide itself. In the rigid main chain structure, the conductivity of the membrane was improved obviously by introducing the branched structure. However, the introduction of branched structure is disadvantageous to the mechanical properties of membranes. 2) the mechanical properties of branched sulfonated polyimide proton exchange membranes are decreased. In this paper, crosslinked sulfonated polyimide proton exchange membranes with branched structure were designed and prepared. The introduction of high branching structure in the main chain can make up for the poor electrical performance of crosslinked sulfonated polyimide proton exchange membranes. And further enhance the chemical stability of the membrane, but also make the membrane material with excellent mechanical properties. More importantly, in the battery testing, this membrane material shows excellent power density. The maximum power density of the membrane is 24% higher than that of the direct crosslinking membrane. This work will provide a new idea for the preparation of high electrical properties crosslinked proton exchange membrane material. 3) the crosslinked sulfonated polyimide can not be dissolved. In order to solve this problem, a sulfonated polyimide containing methoxy silane in side chain was designed and synthesized. The film can be dissolved and repeatedly dissolved and repeatedly prepared. The results showed that the chemical stability of the films prepared by this method was greatly improved and the conductivity decreased. In the direct methanol fuel cell test, the power density of the film prepared by this method decreased only a little, and was much higher than that of the commercial Nafion 212 membrane.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.4;TB383.2

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