添加剂对PVDF/PU复合膜成膜速度、结构与性能的影响

Effects of Additives on Membrane Forming Velocity,Structure and Performance of PVDF/PU Composite Membranes

研究成孔添加剂聚乙二醇(PEG)和LiCl对聚偏氟乙烯(PVDF)/聚氨酯(PU)铸膜液体系的成膜动力学以及膜性能的影响.结果表明:加入PEG、LiCl均能加快成膜速度,膜的水通量有很大程度的提高,而截留率下降.不同相对分子质量PEG对成膜的影响略有不同.相对分子质量越大,黏度因素起到的作用越大,使得成膜速度随相对分子质量增加而稍有降低;相对分子质量越大,截留率下降得越明显;相对分子质量为4.000时,PVDF/PU复合膜的综合性能最好.

The dynamics of membrane formation and performance of PVDF/PU/DMAc/Additive system was studied. The additive was PEG or LiCl respectively. The results show that the rate of membrane formation could be accelerated by the addition of PEG and LiCl. The membrane pure water flux was also improved to a great extent. But the retention decreased. The effect of PEG molecular weight had a little difference on the rate of membrane formation. The larger of molecular weight,the more greatly the viscosity factor acted. And the rate of membrane formation decreased slightly with the increase of PEG molecular weight. The larger of molecular weight,the more obviously the retention decreased. And the proper molecular weight was 4 000 that had the best properties.