半超支化半交联磺化聚酰亚胺复合质子交换膜制备及性能研究

发布时间：2018-01-11 06:06

  本文关键词：半超支化半交联磺化聚酰亚胺复合质子交换膜制备及性能研究　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 有机-无机复合质子交换膜 磺化聚酰亚胺 半交联 半超支化 胺化二氧化硅

【摘要】：质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell, PEMFC)是一种将燃料的化学能通过电化学反应直接转化为电能的装置。其具有环境污染小,噪音低,寿命长,工作温度低,比能量大等优点,在便携式电源、可移动动力电源等方面具有广阔的应用前景。而质子交换膜(PEM)是质子交换膜燃料电池的核心组件,在PEMFC中具有双重作用； (1)作为电解质提供氢离子的传输通道； (2)阻隔阴阳两极,防止两极反应气体接触而发生化学反应。目前,使用最广泛的质子交换膜是由美国杜邦公司开发的全氟磺酸膜,即Nafion(?)膜。它具有优异的热稳定性和化学稳定性,在高湿度的条件下有较高的质子传导率。但是价格昂贵,并且在高温或低湿度条件下质子传导率低,严重限制了其在PEMFC中的广泛应用。因此,研发一种高性能、低成本的质子交换膜非常重要。通过大量的研究发现,磺化聚酰亚胺是一种具有较广应用前景的质子交换膜材料,其主要优势在于：较好的质子传导能力、机械性能和热稳定性以及相对低廉的制备成本。但是,磺化聚酰亚胺膜也存在一些需要解决的问题,包括在水中氧化稳定性差,严重影响燃料电池的使用寿命。为了改善磺化聚酰亚胺膜的氧化稳性能,人们尝试多种改性方法,其中有机-无机杂化是一种常用的方法,其主要优点在于复合膜不仅具有有机物的柔韧性同时具有无机组分的稳定性,因此得到越来越多研究者的关注。本论文选用磺化聚酰亚胺作为质子交换膜主链,聚砜作为支撑材料,通过酸酐封端磺化聚酰亚胺与胺化二氧化硅进一步缩聚制备得到具有半超支化半交联结构的磺化聚酰亚胺复合质子交换膜。其主要内容为：首先合成以酸酐封端的磺化聚酰亚胺链,其次以表面胺化的二氧化硅作为“Bx型胺类单体”,直接与酸酐封端聚酰亚胺进行缩聚,最后加入支撑材料聚砜制备得到复合膜。复合膜中半超支化结构形成的自由体积和胺化二氧化硅可以有效保持复合膜中的水含量,进一步提高复合膜的质子传导率,同时半交联结构和支撑材料聚砜的存在增强了膜的氧化稳定性,延长膜的使用寿命。研究结果表明,30℃下,SPI/SiO2-10-PSf(SiO2含量为10%)复合膜在芬顿试剂中开始溶解和完全溶解的时间比SPI/PSf膜分别增加了14和37小时。SPI/SiO2-10-PSf复合膜在60℃条件下的质子传导率为0.162S·cm-1,高于Nafion115膜(0.124S·cm1-1)。整体上SPI/SiO2-10-PSf复合膜具有较好的综合性能,有望替代Nafion膜,应用于质子交换膜燃料电池中。
[Abstract]:Proton Exchange Membrane Fuel Cell. PEMFC is a device that converts the chemical energy of fuel directly into electric energy by electrochemical reaction, which has the advantages of low environmental pollution, low noise, long life, low working temperature and high specific energy. The proton exchange membrane (PEM) is the core component of the proton exchange membrane fuel cell (PEM), which plays a dual role in PEMFC. 1) providing hydrogen ion transport channel as electrolyte; At present, the most widely used proton exchange membrane is the perfluorinated sulfonic acid membrane developed by DuPont Company of the United States. Membrane. It has excellent thermal and chemical stability, high proton conductivity under high humidity, but high price, and low proton conductivity at high temperature or low humidity. Therefore, it is very important to develop a proton exchange membrane with high performance and low cost. Sulfonated polyimide is a kind of proton exchange membrane material with wide application prospect. Its main advantages lie in better proton conductivity, mechanical properties and thermal stability, and relatively low preparation cost. Sulfonated polyimide membrane also has some problems to be solved, including poor oxidation stability in water, which seriously affects the service life of fuel cell. In order to improve the oxidation stability of sulfonated polyimide membrane. A variety of modification methods have been tried, of which organic-inorganic hybrid is a common method. Its main advantage is that the composite membrane not only has the flexibility of organic matter, but also has the stability of inorganic components. In this thesis, sulfonated polyimide was chosen as the main chain of proton exchange membrane and polysulfone as the supporting material. Sulfonated polyimide composite proton exchange membranes with semi-hyperbranched semi-crosslinked structure were prepared by further condensation of acid anhydride capped sulfonated polyimide and aminated silica. First, sulfonated polyimide chains sealed by anhydride were synthesized. Secondly, the surface aminated silica was used as the "Bx amine monomer", and the polyimide was directly condensed with the acid anhydride terminated polyimide. Finally, the composite membrane was prepared by adding the support material polysulfone. The free volume of semi-hyperbranched structure and the content of water in the composite membrane could be effectively maintained by adding silica amines. The proton conductivity of the composite membrane was further improved, and the existence of semi-crosslinked structure and support material polysulfone enhanced the oxidation stability of the membrane and prolonged the service life of the membrane. The results showed that the membrane was stable at 30 鈩，

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