耐溶剂聚酰亚胺纳滤膜的制备与分离性能

Preparation and Separation Performance of Solvent-Resistant Polyimide Nanofiltration Membrane

本文以均苯四甲酸二酐(PMDA)和4,4′ 二氨基二苯醚(ODA)为原料,采用相转化法制备了耐溶剂的聚酰亚胺(PI)纳滤膜。通过对原料进行预处理,调节反应时间,使得聚酰胺酸(PA)特性粘度稳定在0 99mL g。试验结果表明,当聚酰胺酸铸膜液质量分数为15%,溶剂挥发时间为30min,凝胶浴为乙醇质量分数30%的乙醇 水溶液时,所制得的聚酰亚胺纳滤膜具有最佳的分离性能。操作压力为2MPa时,该膜对聚乙二醇300(PEG300)水溶液截留率可达91%,通量为5 75L (m2·h)。为进一步研究适用于有机溶剂体系的纳滤膜技术提供了基础。

In this study, solvent-resistant nanofiltration polyimide (PI) membrane was prepared from polyamic acid (PA) solution via immersion precipitation phase inversion process. Polyimide precursor was obtained from pyromellitic dianhydride (PMDA) and 4,4′-diaminodiphenyl ether (ODA). By performing the reactants pretreatment, adjusting reaction time, the characteristic viscosity of PA could be stabilized at 0.99 mL/g. The separation performance of the synthesized membrane was evaluated by using PEG300. The membrane prepared by 15% PA, evaporation for 30 min and the gel-bath of 30% ethanol aqueous solution showed a good PEG300 rejection rate up to 91% with a flux of 5.75 L/(m^2·h) when the operation pressure was 2 MPa. The prepared PI membrane will have promising applications in separations of organic solvent systems.