通过羟基聚酰亚胺（HPI）与对氟苯甲酸间的亲核取代反应合成了羧基化聚酰亚胺（CPI），以水为绿色溶剂，采用溶剂挥发法制备了不同羧化度的CPI膜，研究了引入羧基对CPI膜的CO₂、CH₄渗透分离性能的影响。结果表明，随着羧化度的增加，CPI膜的CO₂渗透系数以及CO₂/CH₄的选择性均不断增加，制备的CPI膜打破了trade-off规则。当羧化度为19%、压力为0.1 MPa、温度为25℃时，CO₂的渗透系数为68 Barrer，CO₂/CH₄的选择性达到78，CPI膜比纯HPI膜的CO₂渗透系数和CO₂/CH₄选择性分别提高了467%和224%。

Carboxylated polyimide (CPI) is successfully prepared through nucleophilic substitution reaction between hydroxy polyimide (HPI) and para-fluorobenzoic acid.Furthermore,CPI membranes with different carboxylated degrees are prepared via solvent evaporation method with water as a solvent.The effects of carboxylated degree on CO₂ permeability and CO₂/CH₄ selectivity performance of CPI membranes are studied.It is indicated that both CO₂ permeability and CO₂/CH₄ selectivity of CPI membranes increase obviously with the increase of carboxylated degrees,which breaks the trade-off rule.The CO₂ permeability coefficient and the CO₂/CH₄ selectivity of CPI membranes can reach 68 Barrer and 78 when CPI membranes have a 19wt% of carboxylated degree,pressure is 0.1 MPa and temperature is at 25℃.Compared to pure HPI membrane,CO₂ permeability coefficient and CO₂/CH₄ selectivity of CPI membranes increase by 467% and 224%,respectively.

尹松虎(1990-),男,硕士研究生,主要从事膜材料制备及应用研究,18800582506@163.com。