碳分子筛填充聚醚共聚乙酰胺膜渗透汽化分离水溶液中的醋酸正丁酯

Pervaporation separation of n-butyl acetate from aqueous solution by CMS-filled polyether block amide membrane

将碳分子筛(CMS)引入到聚醚共聚乙酰胺(PEBA)中制备填充膜,采用FTIR、SEM对膜的物理化学结构进行了表征,结果显示CMS与PEBA间未发生化学交联,CMS在膜中分散均匀且与PEBA结合紧密.通过拉伸实验,测定了膜的机械性能.借助溶胀实验,考察了膜在醋酸正丁酯水溶液中的溶胀性能.通过渗透汽化实验,验证了膜的渗透汽化性能,结果表明通量随着温度的升高而增大,分离因子则随温度升高而下降;当料液浓度增大时,醋酸正丁酯的通量和分离因子都显著增大;当CMS填充量为20%时,膜的分离效果最佳,总通量和分离因子分别可达到421.6 g/(m2.h)和590.4.利用Arrhennius方程,关联了通量与温度的关系.另外,还对膜结构与溶液组分的相互作用以及膜中CMS存在通道作用的机理进行了探讨.

CMS was added into polyether block amide （PEBA） for the preparation of filled- membrane. The physical and chemical structure of the membrane was characterized by SEM and FTIR. The results showed that the CMS particles were dispersed uniformly within the polymer phase and a good adherence was obtained between the CMS and PEBA just by physical cross- linking. The mechanical property of the membrane was tested by mechanical strength measurement. The swelling behavior in n - butyl acetate aqueous solution was also studied. The separation performance of the filled - membrane was investigated through PV experiment. PV result indicated that permeation flux increased with rise of temperature, however, separation factor declined when temperature was increasing. Both the permeation flux and separation factor of n - butyl acetate increased with the increase of concentration in the feed. Another significant result was that the largest flux and separation factor were obtained when CMS filling content was 20%, and total permeation flux and separation factor was 4211.6 g/（m3· h） and 590.4, respectively. The relationship between the flux and temperature was related by Arrhennius equation. Finally, a possible PV separation mechanism on the filled - membrane was explored based on the experimental data and membrane structure.