非溶剂对浇铸SPEEK膜性能的影响

Effect of Nonsolvent on the Performance of Cast SPEEK Membranes

首次采用磺化聚醚醚酮/N,N-二甲基甲酰胺(SPEEK/DMF)和非溶剂(四氯乙烯或对二甲苯)组成的铸膜液制备了SPEEK膜。采用交流阻抗法和隔膜扩散法分别考察了膜的质子传导性和透水性能。结果表明,由于在SPEEK/DMF中添加非溶剂,膜的透水率增加了约30%,质子导电率提高了50%左右。非溶剂的加入影响了铸膜液中聚合物的形态、尺寸和团聚情况,从而影响了成膜后膜的性能。本研究提出的控制膜微相结构的新方法将有助于提高SPEEK膜燃料电池性能。

For the first time,membrane casting solution of sulfonated poly（ether ether ketone）（SPEEK） dispersed in the mixture of solvent dimethyl formamide（DMF） and nonsolvent（tetrachloroethylene or para-xylene） was used to prepare SPEEK electrolyte membranes.The proton conductivity,the water uptake and the water permeability of the membranes were measured and compared with those of membrane cast from SPEEK/DMF solution.The proton conductivity and water permeability were increased by around 30% and 50%,respectively.The introduction of nonsolvent to the casting solution caused aggregation of the SPEEK ionomers,which then affected the structure and performance of the resultant membranes.The improvement of proton conductivity and water permeability are of significance to enhancing the performance of polymer electrolyte membrane fuel cells.