Abstract: Membranes containing polyether segments may exhibit high CO₂/N₂ separation performance due to strong affinity between polyether segments and CO₂. Membranes with ethylene oxide (EO) groups are widely investigated, but high crystallinity of membranes with EO groups reduces gas permeance of membranes. Compared with EO group, propylene oxide (PO) group possesses an additional side methyl group that prevents crystallization and increases free volume of the membrane, which promotes gas permeance of the membrane. However, preparation of the composite membrane containing PO groups is rarely reported. In this work, composite membranes containing PO groups were prepared by interfacial polymerization with trimesoyl chloride and polyetheramines containing PO groups. The effects of PO group content and degree of cross-linking on separation performance of the membrane were investigated by using D400, D230 or T403 as the monomer in the aqueous phase. The membrane prepared with D400 exhibited the highest CO₂ permeance and CO₂/N₂ selectivity due to its high PO group content and low degree of cross-linking. Moreover, the effects of monomer concentration, acid acceptor, and pH of the aqueous phase on separation performance of the membranes were also investigated. The high-performance membrane containing PO groups was prepared by optimizing the preparation conditions.

Key words: membrane, separation, solubility selectivity, interfacial polymerization, CO₂ capture

摘要： 含有醚氧基团的膜与CO₂分子具有较强的极性作用,可以实现对CO₂/N₂物系的高效分离.其中,含丙烯氧(PO)基团的聚合物链段自由体积较大且不易结晶,是一类具有发展潜力的溶解选择性膜材料.以均苯三甲酰氯为油相单体,含PO基团的多胺为水相单体,通过界面聚合,成功制备了含PO基团的复合膜.分别采用聚醚胺D400、D230及T403为多胺水相单体,考察了膜内PO基团数量和交联度对复合膜分离性能的影响.结果表明,采用D400所制的复合膜由于具有最高的PO基团含量及较低的交联度,因此具有最高的CO₂渗透速率和CO₂/N₂分离因子.之后,考察了单体浓度、酸吸收剂种类以及水相溶液pH对复合膜分离性能的影响.通过优化这些制膜条件,制备出了CO₂/N₂分离性能较好的复合膜.

关键词: 膜, 分离, 溶解选择, 界面聚合, 二氧化碳捕集