交联嵌段磺化聚芳醚砜质子交换膜的制备及性能

为提高磺化聚芳醚砜(SPAES)质子交换膜的质子传导率及稳定性, 制备了一系列交联嵌段SPAES质子交换膜(cbSPAES). 采用嵌段共聚方法, 在P₂O₅存在下, 利用磺酸基团与聚合物主链上活泼氢的脱水反应进行交联改性合成嵌段聚合物. 采用电化学阻抗谱技术测定了cbSPAES膜的质子传导率, 通过测试水中膜平面及厚度方向的尺寸变化率评价膜的尺寸稳定性, 通过加速老化试验评价膜的水解稳定性. 结果表明, 与未交联膜相比, cbSPAES膜的尺寸稳定性及水解稳定性明显提高; 在交联程度相同时, cbSPAES膜的吸水率和质子传导率随着磺化链段长度的增加呈上升的趋势. 如cbSPAES(30/10)-10膜在60 ℃水中的吸水率为65%, 平面方向和厚度方向的尺寸变化率分别为0.16和0.18, 质子传导率达到163 mS/cm.

Synthesis and Properties of Proton Exchange Membranes Based on Cross-linked Block Sulfonated Poly(arylene ether sulfone)s

In order to improve the proton conductivity and stability of proton exchange membranes based on sulfonated poly(arylene ether sulfone)(SPAES), a series of cross-linked block SPAES membranes(cbSPAES) was prepared. The block SPAES copolymers were synthesized through block copolymerization and subsequently subjected to cross-linking modification in the presence of P₂O₅, where the cross-linking reaction taken place between -SO₃H groups and active hydrogen atoms attached to the polymer backbones. Proton conductivity of the cbSPAES membranes were obtained by electrochemical impedance spectroscopy(EIS), dimensional and hydrolytic stabilities were evaluated by the membrane size changes in the in-plane/through-plane directions and accelerating aging test in water, respectively. The results indicate: (1) cbSPAES membranes have obvious better dimensional and hydrolytic stabilities than SPAES membranes; (2) at the same cross-linking degree, water uptakes and proton conductivities of cbSPAES membranes increase with the increase in repeat units of sulfonated moieties. For example, the membrane of cbSPAES(30/10)-10 exhibits water uptake of 65%, size changes in the in-plane/through-plane directions of 0.16/0.18 and proton conductivity of 163 mS/cm in water at 60 ℃.