丙烯腈-对苯乙烯磺酸共聚物质子交换膜的合成与性能

Synthesis and Performance of Acrylonitrile-Styrenesulfonic Acid Copolymer Proton Conducting Membrane

采用沉淀共聚法制备丙烯腈-对苯乙烯磺酸钠(AN-SSNa)共聚物,成膜酸化得到丙烯腈-对苯乙烯磺酸(AN-SSA)共聚物质子交换膜,研究了SSNa含量对AN-SSNa共聚物水溶性及SSA单元含量对AN-SSA共聚物质子交换膜吸水率、离子交换容量(IEC)、甲醇渗透率和电导率的影响。结果表明当共聚物中SSNa含量为0～4.7%(mol)时,AN-SSNa共聚物不溶于水;随着AN-SSA共聚物中SSA单元含量增大,质子交换膜的吸水率、IEC和甲醇渗透率均增大。用交流阻抗法测定AN-SSA共聚物质子交换膜的电导率,发现膜的电导率也随SSA含量增大而增大。定义膜的电导率与甲醇渗透率之比为膜的选择性系数,发现采用SSA含量为3.12%(mol)的AN-SSA共聚物制备的质子交换膜的选择性系数最大。

Acrylonitrile-sodium styrenesulfonate（AN-SSNa） copolymers were synthesized by precipitation copolymerization,and protonated to obtain the proton-conducting acrylonitrile-styrenesulfonic acid（AN-SSA） copolymer membranes with different solfonation degrees.The influence of SSNa content in AN-SSNa copolymer on the solubility of the copolymer in water,and the influence of SSA content in AN-SSA copolymer on the water uptake,ion exchange capacity,methanol permeation coefficient and proton conductivity of AN-SSA copolymer membranes were investigated.It was found that the AN-SSNa copolymers with 0～4.7%（mol） SSNa could not be dissolved in water.All the water uptake,ion exchange capacity and methanol permeation coefficient of AN-SSA copolymer membranes increase with the increase of SSA content in the copolymers.The proton conductivity of AN-SSA copolymer membranes determined by AC impedance method also increases with the increase of SSA content in the copolymers.It was also found that the membrane prepared with AN-SSA copolymer containing 3.12%（mol） SSA has the maximum membrane selectivity which was defined as the ratio of the proton conductivity to methanol permeation coefficient of the membrane.