PREPARATION OF HOLLOW FIBER TYPE PERVAPORATION MEMBRANES FOR ORGANIC-LIQUID SEPARATION MADE BY PLASMA-GRAFT FILLING POLYMERIZATION

采用等离子体接枝填充聚合法制备了中空纤维型渗透蒸发膜。膜由两种不同的聚合物组成；一种可抑制膜膨胀的多孔底物，以及一种在底物的孔中形成并由于其溶解度而表现出选择性的接枝聚合物。具体来说，多孔高密度聚乙烯膜和聚甲基丙烯酸酯分别被用作多孔基底和接枝聚合物。通过该技术，接枝聚合物在基体的孔隙中形成，接枝层的厚度在20mum左右。用该膜对苯/环己烷或氯仿/四氯化碳进行渗透汽化分离。中空纤维基材的机械强度弱于平片状膜，渗透蒸发选择性也低于平片状膜。采用交联和共聚技术减少了膜的膨胀。这两种方法都使我们获得了更高的选择性，但牺牲了渗透率。利用这些方法，我们获得了具有与平板膜相同分离性能的中空纤维膜。

Hollow fiber type pervaporation membranes were successfully prepared by plasma-graft filling polymerization. The membrane is composed of two different polymers ; a porous substrate which can suppress membrane swelling, and a grafted polymer whic forms in the pores of the substrate and exhibits selectivity due to its solubility. Specifically, a porous high-density polyethylene membrane and poly (methylacrylate) were emlployed as the porous substrate and grafted polymer, respectively. Through this technique, the grafted polymer was formed in the pores of the substrate, and the thickness of the grafted layr was around 20mum. Pervaporation separation of benzene/cyclohexane or chloroform/carbontetrachloride were performed with the membranes. The mechanical strength of hollow-fiber substrate was weaker than flat sheet membranes, and the pervaporation selectivity was lower than the membranes. Crosslinking and copolymerization technique were employed to reduce the membrane swelling. Both method allowed us to obtain higher selectivity although permeability was sacrificed. Using these method, we obtained a hollow-fiber membranes having the same level of separation performances that the flat sheet membrane showed.