磺化聚芳酸砜类侧链型质子交换膜的制备及改性

发布时间：2018-07-03 03:41

  本文选题：磺化聚芳醚砜 + 侧链　； 参考：《南京理工大学》2015年硕士论文

【摘要】：作为燃料电池用的电解质膜,全氟聚合物膜因为其优异的化学和物理稳定性,高湿低温下的高质子电导率而被广泛应用,例如Nafion和Flemion系列。然而,它们也存在着操作温度低、成本高、燃料渗透率高等缺点。为了克服这些缺点,学者们开始研究低成本、高效率的芳香族质子交换膜。本论文致力于开发新型的侧链型质子交换膜材料,通过交联、复合等方法进一步进行材料改性,并对其性能与结构的关系进行了讨论,主要包括质子电导率、吸水率、尺寸变化、水解稳定性、机械强度等。以十氟联苯、4'4-二羟基二苯砜及2-萘酚-6,8-二磺酸钾为原料通过亲核取代反应制备了一系列新型磺化聚醚砜质子交换膜SPES-NDSx。所制备的膜(IEC=1.22-2.07 mmol/g)表现出极低的吸水率(27-58%)及优异的尺寸稳定性。60℃下,SPES-NDS60(1.68 mmol/g)的电导率达到124 mS/cm,吸水率仅为40%。在合成SPES-NDSx及磺化聚酰亚胺(SPI)两种聚合物的基础上,采用不同配比,制备了一系列SPES-NDSx/SPI复合型质子交换膜,并对其性能进行了研究。结果表明,由于SPI的引入,复合膜的尺寸稳定性及机械性能都有了较大的提高,它们的水解稳定性也大大提高,在140℃水中高温处理24h后,所有复合膜都仍然具有Ⅳ级以上的稳定度,重量损失也都控制在6%以内。虽然复合膜的质子电导率随着SPI含量比例的增加而降低,但SPES-NDS70/SPI系列都显示出高于Nafion112的质子电导率,表现出良好的综合性能。在合成嵌段型非磺化聚合物主链的基础上,通过引入磺化低聚物作为接枝侧链,成功制备了一系列具有不同磺化度及交联度的磺化聚醚砜质子交换膜bSPAES。因为交联及侧链磺化结构的影响,所有膜都表现出优异的尺寸稳定性,例如60℃下,所有膜的平面方向尺寸变化都在3%以内,厚度方向控制在7-16%,尺寸变化的各向异性尤其满足燃料电池的运行需要。同时,bSPAES膜在较低离子交换容量的水平下保持了较高的电导率,其中,bSPAES-5/5膜在整个温度范围内都表现出与Nafion112相当的电导率,并具有比Nafion112更优异的尺寸性能。
[Abstract]:As electrolyte membranes for fuel cells, perfluoropolymer membranes are widely used because of their excellent chemical and physical stability, high proton conductivity at high humidity and low temperature, such as Nafion and Flemion series. However, they also have the disadvantages of low operating temperature, high cost and high fuel permeability. To overcome these shortcomings, researchers have begun to study low-cost, high-efficiency aromatic proton exchange membranes. This paper is devoted to the development of new side chain proton exchange membrane materials. The properties of the materials are further modified by crosslinking and recombination, and the relationship between the properties and the structure is discussed, including the proton conductivity, water absorption, and so on. Size change, hydrolysis stability, mechanical strength, etc. A series of novel sulfonated polyether sulfone proton exchange membranes SPES-NDSx were prepared by nucleophilic substitution reaction with decafluorinated biphenyl 4- dihydroxy diphenyl sulfone and 2-naphthol -6o 8-disulfonic acid potassium as raw materials. The prepared membranes (IECs 1.22-2.07 mmol/g) showed extremely low water absorption (27-58%) and excellent dimensional stability. The conductivity of SPES-NDS60 (1.68 mmol/g) was 124mS-1 路cmand the water absorption was only 40mS-1 路cm. Based on the synthesis of SPES-NDSx and sulfonated polyimide (SPI), a series of SPES-NDSx / SPI composite proton exchange membranes were prepared and their properties were studied. The results showed that the dimensional stability and mechanical properties of the composite membranes were greatly improved and the hydrolysis stability was greatly improved because of the introduction of SPI. The composite membranes were treated at high temperature at 140 鈩，

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