新型聚苯并咪唑树脂的微波合成及质子交换膜的性能

采用微波合成法, 调整己二酸和2,6-吡啶二甲酸2种二酸单体的配比, 使其与联苯四胺进行三元共聚, 制备出一系列新型含脂肪链结构的聚苯并咪唑(PBI)类质子交换膜, 并用红外光谱、 热重分析进行了表征, 对膜的吸水率、 溶胀率、 质子传导率、 机械强度及抗氧化性能等进行了测试. 当己二酸与2,6-吡啶二甲酸的摩尔比为3: 2时, 所制备的PBI-C₂膜掺杂磷酸后在160℃下的质子传导率可达30 mS/cm, 拉伸强度在常温下可达77.54 MPa, 断裂伸长率为39.25%, 最大储能模量为9.0623 MPa, 最大损耗模量为8.36 MPa, 玻璃化转变温度为360℃, 芬顿试验192 h后膜的降解率仅为0.21%, 表明PBI-C₂膜在高温质子交换膜燃料电池中具有较好的应用前景.

Microwave-Assisted Synthesis of Novel Polybenzimidazole Resin and Performance of Its Proton Exchange Membranes

A series of novel aliphatic polybenzimidazole(PBI) copolymers was synthesized from 3,3'-diaminobenzidine, adipic acid and 2,6-pyridinedicarboxylic acid by adjusting the molar ratio of adipic acid and 2,6-pyridinedicarboxylic acid via solution condensation reaction in poly(phosphoric acid) with microwave synthetic method which is timesaving relative to conventional ways. The casting PBI membranes made from the copolymers were characterized mainly by Fourier transform infrared spectrometer(FTIR), thermogravimetric analyzer(TGA), water uptaking, swelling ratio, proton conductivity, tensile strength as well as Fenton test. Among the membranes, the PBI-C2 membrane made from the resin by polymerization using adipic acid and 2,6-pyridinedicarboxylic acid in a molar ratio of 3: 2, showed good proton conductivity as high as 30 mS/cm at 160℃ after doped with H3PO4. The tensile strength(77.54 MPa) and elongation at break(39.25%) were measured at room temperature. By dynamic mechanical thermal analysis(DMTA), the parameters including the maximum storage modulus(9.0623 MPa), the maximum loss modulus(8.36 MPa) and glass transition temperature(360℃) were obtained. The Fenton test indicates that PBI-C2 membrane has good anti-oxidative stability. The results suggest that the PBI-C2 membranes show a promising application in high temperature proton exchange membrane fuel cell.