全氟磺酸树脂中空纤维膜的离子交换性能的研究

本文采用静态和动态离子交换两种方法,对全氟磺酸树脂中空纤维膜的离子交换性能进行了研究。结果表明在静态离子交换过程中,膜的交换能力随着时间增加而增加,最后趋于一平衡值;金属离子的种类对膜的交换能力有很大的影响。在动态离子交换过程中,膜的交换能力随温度升高而增加。并测定了静态和动态交换过程中的各扩散系数。     

全氟磺酸中空纤维膜基本性能研究

本文用 EW=1563的 Nafion 树脂为原料,纺制了内径为0.44mm,外径为1mm 的中空纤维膜,并将其转化成 K 型、Na 型和 H 型。研究了不同类型的 Nafion 中空纤维膜对水的吸附行为,并初步探讨了 Nafion-H 中空纤维膜对极性不同的两种液体的分离效果。结果表明,水在Nafion 中空纤维膜中的扩散系数与膜中阳离子半径有关,阳离子半径愈小,扩散系数愈大;水在Nafion-K 中空膜中的扩散系数随温度的升高而增加,求得的扩散活化能为44KJ/mol;同时还表明,Nafion-H 中空纤维膜对甲苯-乙醇混合溶液透过蒸发的分离效果良好。     

A STUDY OF RHEOLOGICAL PROPERTIES OF NAFION IONOMER MELT IN CAPILLARY FLOW

Nation(a branched perfluorosulfonate ionomer)is a kind of functional polymer materialwhich can be processed to different forms for various uses,such as electrolytic membrane or sep-aration hollow fiber,by conventional melt processing methods.In order to optimize the pro-cessing conditions of the polymer,the rheological properties of Nation ionomer in capillary flowwere studied and the flow behaviors of the polymer melt were also investigated.The resultsshowed that the value of non-Newtonian Index for Nation melt is reached up to 0.92 at 250℃and the viscosity shear—rate dependence of the polymer melt is minimized at the same tempera-ture.The polymer melt has the values of activation energies(61.5 KJ/mol to 12.5 KJ/mol atthe shear rate 0.42 s~(-1) to 140 s~(-1))which is much lower than conventional polymer melts,such aspolyethylene terephthalate,polyamides,polypropylene etc.and the suitable processing tempera-ture of Nation ionomer for hollow fibres was proposed in the work.