Gas Transport Properties of Asymmetric Block Copolyimide Membranes
Gas Transport Properties of Asymmetric Block Copolyimide Membranes
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DOI：
10.1295/polymj.pj2009108
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发表时间：
2009-01-01
期刊：
影响因子：
2.8
通讯作者：
Kawakami, Hiroyoshi
中科院分区：
文献类型：
--
作者：
Kashimura, Yumi;Aoyama, Satoshi;Kawakami, Hiroyoshi
采用两锅法合成了不同嵌段长度的含氟嵌段共聚酰亚胺，并采用干湿相转化法制备了不对称共聚酰亚胺膜。使用配备有Baratron绝对压力计的高真空装置在76 cmHg和35 ℃下测量不对称膜的气体传输性能。我们证明了非对称膜的表皮层厚度和气体传输性能取决于共聚酰亚胺的结构。嵌段共聚酰亚胺溶液中的相分离瞬间发生，使得不对称嵌段共聚酰亚胺膜的表层变得比不对称无规共聚酰亚胺膜的表层薄，并且不对称嵌段共聚酰亚胺膜的气体渗透性具有高值。非对称嵌段聚酰亚胺膜的表观表层厚度为230 nm。不对称共聚酰亚胺膜显示2.7 × 10 - 4 [cm（3）（STP）/（cm（2）sec cmHg）]（270 [GPU]）的O-2渗透性和4.3的O-2/N-2选择性。
We have synthesized fluorinated block copolyimides with different block chain lengths by chemical imidization in a two-pot procedure and prepared the asymmetric coployimide membranes using the dry-wet phase inversion process. The gas transport properties of the asymmetric membranes were measured using a high vacuum apparatus equipped with a Baratron absolute pressure gauge at 76 cmHg and 35 degrees C. We demonstrated that the skin layer thicknesses and the gas transport properties of the asymmetric membranes depended on the copolyimide structures. The phase separation in the block copolyimide solution instantaneously occurred so that the skin layer of the asymmetric block copolyimide membrane became thinner than that of the asymmetric random copolyimide membrane and the gas permeance of the asymmetric block copolyimide membrane had a high value. The apparent skin layer thickness of the asymmetric block coployimide membrane was 230 nm. The asymmetric copolyimide membrane indicated an O-2 permeance of 2.7 x 10(-4) [cm(3) (STP) /(cm(2) sec cmHg)] (270 [GPU]) and an O-2/N-2 selectivity of 4.3.