溶剂对溶液法制备的SPEEK质子交换膜性能的影响

Effect of solvents on properties of SPEEK proton exchange membranes prepared with the solution method

本文在聚醚醚酮(PEEK)磺化反应制备相同磺化度的磺化聚醚醚酮(SPEEK)基础上,采用不同的溶剂通过溶液法制备一系列SPEEK质子交换膜,采取交流阻抗法、扩散池法和溶胀法分别评价其导质子能力、阻醇性能和溶液稳定性,探讨溶剂种类对SPEEK质子交换膜性能的影响规律.试验结果表明溶剂对所制备膜的导质子能力和阻醇性能影响依赖于溶剂分子与SPEEK中磺酸基团的相互作用,若存在越强作用,膜的导质子能力越弱,而阻醇性能越高.此外,溶剂种类对膜的吸水溶胀性能存在较小的影响,对膜表面的微孔形态存在明显的影响,并与膜的导质子能力及阻醇性能存在对应关系.综合比较不同溶剂制备膜的导质子能力、阻醇性能和吸水溶胀性能,DMAc是优于DMF和DMSo的制膜溶剂.

The SPEEK membranes were prepared by the solution method using different solvents and SPEEK with the same degree of sulfonation. Through the AC resistance measurement, the methanol diffusion measurement and the corrosion measurement, the properties of SPEEK membranes including the conductivity, the methanol diffusion resistance and the stability in solution were evaluated. Effects of solvent types on the performances of SPEEK membranes were investigated. It was showed that the influence of the solvent type on the conductivity and the methanol diffusion resistance of these membranes would depend on the interaction between the solvent and the sulfonic group in SPEEK. If the interaction increased, the conductivity would decrease, however, the methanol diffusion resistance increased. The type of the solvent had a little effect on the stability of the membrane in water and an apparent influence on the micro - hole morphology of the membrane surface, which had the relationship with the conductivity and the methanol diffusion resistance of the membranes. By comparing the conductivity and methanol diffusion resistance, DMAc was better than DMF and DMSO used as the solvent for preparing membranes.