改性聚酰亚胺膜的水蒸气渗透性和空气除湿性能

考察了改性聚酰亚胺(P I)膜的亲水性、水蒸气渗透性、制膜混合溶液的表观粘度。结果表明:随着季胺盐含量的增加,膜的亲水性增强,水分子的渗透系数增加,同时水分子的渗透受膜的厚度和相对湿度的影响,制膜混合溶液的表观粘度增大,出现了盐增粘现象。测试了一系列共混改性中空纤维膜组件的除湿性能,增大压力和增加吹扫气流量,对组件除湿十分有利,尽管在低吹扫气量的情况下,组件的除湿性能并不是一直随着膜的亲水性增强而提高,但是适当增加亲水性盐的含量,膜的除湿性能会得到有效改善。

Water Vapor Permeation and Air Dehydration Properties of Modified Polyimide Membranes

The hydrophilicities,water vapor permeation of a series of modified polyimide(PI) membranes,and the apparent viscosities of their mixed solutions were investigated.The results show that the membrane hydrophilicities and water vapor permeation increased with increasing of quaternary ammonium salt,at the same time,water vapor permeation is affected by membrane thickness and relative humidity,blend solution viscosities raise with increasing quaternarg ammonium salt in PI,and an enhancement phenomena of blend solution is observed.The dehydration properties of blend hollow fiber membranes are tested and it is found that increase of the feed pressure and the sweep flux favor the dehydration performances of blend membranes.Although the properties of membranes are not always improved with the(increasing) the membrane hydrophilicities,but when increase the quantity of quaternary ammonium salt(appropriately,) the dehydration properties of blend hollow fiber membranes would be improved effectively.