基于半互穿聚合物网络的高温质子交换膜的制备

通过构筑基于含不饱和双键的磺化聚芳醚酮(Allyl-SPAEK)与芳醚型聚苯并咪唑(PBI)的半互穿聚合 物网络(IPN), 获得综合性能优异的可用于高温质子交换膜燃料电池的PBI/Allyl-SPAEK复合膜材料. 在对 Allyl-SPAEK和PBI的分子进行设计和合成的基础上, 采用溶液共混-浇铸方法, 基于UV辐照交联, 获得了由丙烯基生成的共价键和咪唑基-磺酸基形成的强酸碱相互作用组成的IPN新体系, 并系统研究了新型复合膜的热、 机械性能和质子传导率. 结果表明, 具有PBI/Allyl-SPAEK半互穿聚合物网络的复合膜具有较高的质子 传导率和力学性能, 在同等磷酸吸附水平和测试条件下优于PBI膜. 在磷酸吸附水平为13.0左右时, PBI/ Allyl-SPAEK复合膜的最大拉伸强度达到12.1 MPa, 杨氏模量达到131.5 MPa, 是同等磷酸吸附水平下 PBI 膜的2.04倍. 在200 ℃时, 两种PBI/Allyl-SPAEK复合膜的质子传导率均达到 200 mS/cm以上, 比PBI膜传导率提高了38%.

Preparation of High-temperature Proton Exchange Membranes Based on Semi-interpenetrating Polymer Networks

To realize the tradeoff between high proton conductivity and high mechanical strength， a semi- interpenetrating polymer network（PIN） based on a sulfonated poly（aryl ether ketone） bearing unsaturated double bonds（Allyl-SPAEK） and an arylether-type polybenzimidazole（PBI） has been fabricated for high- temperature proton exchange membranes in fuel cells. Based on the molecular design and syntheses of Allyl-SPAEK and PBI， a new IPN system composed of covalent bond formed by allyl groups and strong acid-base interactions formed by imidazole-sulfonic acid groups was obtained through a process of solution casting and UV irradiation. The results showed that the PBI/Allyl-SPAEK membranes could have simultaneously improved proton conductivity and mechanical strength， which were much better than the pristine PBI membrane under the same phosphoric acid adsorption level and test conditions. With a phosphoric acid adsorption level of ca.13.0， the maximum tensile strength of one PBI/Allyl-SPAEK membrane was 12.1 MPa， and its young’s modulus reached 131.5 MPa， which was twice of the pristine PBI membrane. At 200 ℃， the proton conductivities of two membranes reached above 200 mS/cm， which was 38% higher than that of the pristine PBI membrane.