聚醚共聚酰胺膜的制备与分离性能

摘要

Block copolymer poly (amide-12-b-ethylene oxide) (Pebax1074) is used to prepare the hydrophilic dense membrane by casting method.Due to the specific affinity of PEO segment to polar gas CO2,Pebax1074 membrane shows high CO2 permeability and CO2/light gas selectivity.Due to CO2 induced plasticization effect,the CO2 permeability increases with increasing pressure,which is more obvious at low temperature.The permeabilities of N2 、CH4 and H2,however,decrease with increasing pressure due to the hydrostatic pressure effect,which decreases with increasing temperature.The relationship between gas permeability and operating temperature can be described by Arrhenius equation.With increasing pressure,the activation energies of permeation for N2 、CH4 and H2 decrease,whereas that for CO2 increases.%以橡胶态聚醚共聚酰胺(Pebax1074)嵌段共聚物为膜材料,采用流延法制备亲水性无缺陷的Pebax1074均质膜.由于Pebax1074嵌段高分子中的聚环氧乙烷(PEO)链段对CO2分子的亲和性,Pebax1074膜对CQ/非极性气体分离体系有较高的分离性能.CO2渗透系数由于增塑作用随膜两侧压差的增大而显著增大,且温度越低增塑作用越大;而N2、CH4和H2等非极性气体的渗透系数由于流体静力学压力效应随膜两侧压差增大略有减小,温度越高流体静力学压力效应越弱.N2、CH4、H2和CO2在Pebax1074膜中的渗透系数均可用Arrhenius方程描述,且随着压力的升高,CO2的渗透活化能下降,而N2、CH4和H2非极性气体的渗透活化能升高.