磺化聚苯乙烯/聚乙烯醇交联膜的制备与性能

Preparation and properties of crosslinked sulfonated polystyrene/polyvinyl alcohol membranes

以磺化度为75%的磺化聚苯乙烯(SPS)和聚乙烯醇(PVA)为原料,按一定的配比共混后浇铸成膜,在程序升温的过程中进行热交联,通过控制不同交联时间得到不同交联密度的交联膜.考察了交联膜的离子交换容量(IEC)、吸水率、溶胀性和尺寸稳定性;利用原子力显微镜和交流阻抗仪对交联膜的表面形貌及电导率进行了表征.结果表明:交联膜的IEC值略有降低;吸水率和溶胀度得到了很好的控制,具有较好的尺寸稳定性;膜表面出现了明显的亲水相和憎水相相分离,且亲水相微区的聚集尺寸和连续性随交联时间的长短而变化;随交联时间的延长,交联膜的电导率值略有下降,但交联后膜的室温电导率仍高于0.01 S/cm.

A series of crosslinked membranes of sulfonated polystyrene（SPS） and polyvinyl alcohol（PVA） were prepared via the method of heating crosslinking,where the sulfonation degree of SPS is 75%.The properties of membranes were investigated.The crosslinking decreases the IEC very lightly.Compared with the uncrosslinked membranes the crosslinked membranes have much lower but enough water uptake and lower swelling ratio.The results also showed that there is a significant phase separation between hydrophilic phase and hydrophobic phase at the surface of crosslinked membranes.The aggregation size and continuity of hydrophilic phase changes with the crosslinking time.The room temperature proton conductivity of the crosslinked membranes at 100% relative humidity decreases with increasing crosslinking time but still higher than 0.01 S/cm.