可重复使用型耐溶剂聚酰亚胺纳滤膜的研制

Preparation of the Polyimide Solvent-Resistant Nanofiltration Membrane with Recyclable Property

以芳香二酐和自制的3,3'-二甲基-4,4'-二氨基二苯甲烷(DMMDA)二胺为单体,N-甲基吡咯烷酮(NMP)为溶剂,从分子结构的角度出发,设计合成了聚酰胺酸溶液,经化学亚胺化反应制备了高相对分子质量的可溶性聚酰亚胺材料,进一步通过浸没-沉淀相转化法制备出聚酰亚胺基纳滤膜。通过红外光谱、核磁、热重分析、扫描电镜、原子力显微镜等对合成单体和聚酰亚胺基纳滤膜的结构和性能进行了分析和表征。结果表明,成功地合成了DMMDA二胺单体,以该单体为原料制备的聚酰亚胺基纳滤膜具有较高的分离性能,对酸性红94的截留率高达92%,同时具有良好的耐溶剂性及重复使用性。

A novel polyamide acid was designed and prepared by choosing aromatic dianhydride and 3,3′- dimethyl-4,4′-diaminodiphenylmethane （DMMDA） diamine which was home-made as monomer, and N-methylpyrrolidone （NMP） as solvent from the perspective of the molecular structure. Then the soluble polyimide materials with high molecular weight were prepared through chemical imidization. Furthermore, the polyimide based nanofiltration membranes were obtained by phase inversion. The synthesized monomer and the structure and properties of the polyimide based nanofiltration membranes were analyzed and characterized by FT-IR, NMR, TG, SEM and AFM. The results show that the monomer is successfully synthesized and such polyimide based nanofiltration membrane exhibits excellent separation performance, showing more than 92% retention on Rose Bengal （RB）. Besides, the membranes possess good solvent-resistant and recyclable performance.