Characterization of Proton-exchange Membrane with Controlled Intramembrane Structure for Fuel Cell

采用等离子体聚合法制备了带有丙烯酸或磺酸盐固定电荷的膜。以聚丙烯（CG）或聚乙烯（HP）微孔膜为基膜，在带有外电极和共轭液槽的等离子体反应器中进行气相聚合，然后在液相中进行后聚合，制备了丙烯酸接枝膜。以三氟甲烷磺酸盐和六氟丙烯为原料，在钟罩式等离子体反应器中，采用内电极气相聚合法制备了氟磺酸盐荷电膜。实验考察了等离子体压力、射频功率和聚合时间等操作条件对荷电膜接枝率、离子交换容量、膜电导率和阳离子迁移数等性能的影响。丙烯酸接枝膜具有较高的含水量，并表现出较高的膜电导率。接枝膜在CG膜上的阳离子迁移数比在HP膜上的高。氟磺酸盐接枝膜的电阻率比Nofion 117膜低，离子交换容量与Nafion相当，阳离子迁移数高。

The membranes having acrylic acid or sulfonate fixed charges were prepared by plasma polymerization. Acrylic acid grafted membranes were prepared by gas phase polymerization in a plasma reactor with outer electrodes and a conjugate liquid vessel, followed by post-polymerization in the liquid phase on the microporous flim of polypropylene (CG) or polyethylene (HP) as a base film. Fluorosulfonate charged-membranes were prepared by gas phase polymerization of both surfaces of the base film in a bell-jar type plasma reactor with inner electrodes, using trifluoromethane sulfonate and hexafluoropropylene. The effects of the operational conditions of plasma pressure ; the RF power and the polymerization period, on the properties of a charged-membrane of the grafting degree ; the ion-exchange capacity, the membrane conductivity and cation transference number, were examined experimentally. Acrylic acid-grafted membranes had high water content, and showed the high membrane conductivity. The transference number of cations of the grafted membrane on the CG film was higher than that of the membrane on the HP film. Fluoro-sulfonate grafted membranes showed the lower resistivity than Nofion 117 membrane, and had the ion-exchange capacity competitive to Nafion and the high transference number of cations.