磺化聚醚醚酮／磷酸锆复合质子交换膜的制备及性能

Preparation and characterization of sulfonated polyether ether ketone/zirconium phosphate composite proton exchange membranes obtained by sol-gel process

采用溶胶?凝胶法原位生成磷酸锆,制备磺化聚醚醚酮/磷酸锆复合质子交换膜。采用扫描电镜观察复合膜的断面形貌;采用热重分析仪研究复合膜的热稳定性;采用气相色谱测量并计算了复合膜的阻醇性;采用交流阻抗法测量复合膜的质子传导率;同时还研究复合膜的吸水率、尺寸稳定性。研究结果表明:复合膜中磷酸锆呈无定形状态,与有机基体结合紧密;随着磷酸锆含量的增加,复合膜的热稳定性、尺寸稳定性和阻醇性能提高,吸水率降低,当磷酸锆含量(质量分数)为30%时,复合膜的甲醇渗透系数比磺化聚醚醚酮(sPEEK)膜降低47.5%;在100%相对湿度下,复合膜的稳定温度随磷酸锆的含量增加而升高,含磷酸锆20%以上的复合膜在80℃时仍稳定;质子传导率在低温下略有降低,但随温度的升高,质子传导率有所增加,当温度为80℃时,质子传导率与Nafion115膜的传导率相当。

The sulfonated polyether ether ketone（sPEEK）/zirconium phosphate composite proton exchange membranes were prepared by a sol-gel process in which zirconium phosphates were formed in-situ in the organic solution. The microstructures of composite membranes were studied by XRD and SEM. The thermal stabilities, methanol permeabilities and proton conductivities were investigated. Water uptakes and dimensional stabilities were also studied. The results indicate that amorphous zirconium phosphates are formed in the composite membrane, and have a good combination with the organic phase. The thermal stabilities and dimensional stabilities increase, while the water absorptions and methanol permeabilities decrease with the contents of zirconium phosphates increasing. The methanol permeability coefficient of composite membrane is 47.5% lower than that of sPEEK membrane. The temperatures making the composite membranes stable increase as the contents of zirconium phosphates increasing at 100% relative humidity. The temperature reaches 80 ℃ when the content is 20%. The proton conductivities decrease at low temperatures, and increase with the increase of temperature. The proton conductivities is equivalent to that of Nafion115 when the temperature is 80 ℃.