含全氟环丁基的嵌段型质子交换膜材料的设计、合成及结构与性能关系研究

Polymer exchange membrane fuel cell technology, which directly converts the chemical energy of hydrogen and oxygen into electrical energy, is of great practical importance for easing the problems of energy shortage and environmental pollution in China, due to its advantages such as high efficiency, environmental compatibility and wide applications. In view of the poor performances of the traditional aromatic hydrocarbon-type proton exchange membranes (PEMs) under medium temperature and low relative humidity, novel block-type PEM materials based on perfluorocyclobutyl aryl ether polymers were proposed in this proposal. A series of sulfonated block copolymers containing perfluorocyclobutyl groups will be synthesized, via constructing the polymer main chains by nucleophilic polycondensation reaction and incorporating the sulfonated side chains by graft. The polymers will be characterized by NMR, FT-IR, DSC and TGA. The properties of the polymer membranes such as water uptake and dimensional/chemical stability will be investigated. The effect of fluorine content, degree of sulfonation, the structures of main/side chains and the length of the blocks on the properties of the membranes will be discussed. The morphology of the membranes will be investigated by SEM, TEM and SAXS; and the structure-morphology-property relationships will be established. This proposal aims to explore how to improve the micro-phase separation morphology of the membranes from the level of polymer architecture design, to improve the properties of the membranes under medium-temperature and low relative humidity, which is expected for providing new ideas and theoretical basis for the design and development of new PEM materials.

质子交换膜燃料电池技术能将氢和氧的化学能直接转换成电能，具有高效、环境友好和应用广泛等特点, 对缓解我国能源紧张和环境污染问题具有重要的现实意义。针对目前传统芳香碳氢型质子交换膜(PEM)在中温、低相对湿度条件下性能差的问题，本申请提出利用全氟环丁基芳基醚聚合物构建新型嵌段型PEM材料。通过亲核缩聚反应构建嵌段共聚物的主链和采用接枝的方法引入磺化侧链，合成一系列含全氟环丁基的磺化嵌段共聚物。利用NMR、FT-IR、DSC和TGA对聚合物进行表征。考察磺化聚合物膜的质子传导率、尺寸和氧化稳定性等性能，研究含氟量、磺化度、主侧链结构以及嵌段长度对膜性能的影响。利用TEM、SEM和SAXS考察膜的微相分离形态，建立膜的结构、形态、性能之间的关系，探讨如何从聚合物结构设计层面来改善聚合物膜的微相分离形态，提高膜在中温、低相对湿度条件下的性能，以期为新型PEM材料的设计与开发提供新思路和理论依据。

全氟环丁基芳基醚聚合物是一类新型的部分氟化聚合物，高的热、氧化和化学稳定性以及良好的可加工性等优异性能，在涂料、航空材料和光学材料等领域具有潜在的应用前景。针对目前传统芳香碳氢型质子交换膜在中温、低相对湿度条件下性能差的问题，本项目提出利用全氟环丁基芳基醚聚合物构建新型PEM材料。首先设计、合成含反应性基团（苄基或酚羟基）的全氟环丁基芳基醚聚合物，然后利用后功能化策略，将不同的磺化侧链引入到聚合物主链上，最后制得不同类型含全氟环丁基的质子交换膜材料。利用核磁共振光谱、红外光谱、凝胶渗透色谱法以及热重分析等对聚合物进行了表征，同时对部分聚合物的电化学性能进行了研究。结果表明，部分聚合物的具有较高的分子量、良好的热稳定和电化学性能。该项目为全氟环丁基芳基醚聚合物的后功能化及其在质子交换膜材料方面的应用提供了新思路。