牵引速率对聚丙烯中空纤维膜结构与性能的影响

Effects of Drawn Rate on the Structure and Properties of Polypropylene Hollow Fiber Membranes

采用熔纺-拉伸法制备了一系列聚丙烯中空纤维膜。研究了牵引速率对中空纤维及微孔膜的结晶性、弹性回复率、表观形貌等性能的影响。结果表明:牵引速率对聚丙烯中空纤维的结晶行为有较大影响,牵引速率越大,越有利于shish-kebab晶体的形成与均匀分布,从而改善纤维的硬弹性;随着牵引速率的提高,中空纤维膜的表面结构发生相应变化,同时其孔隙率和水通量均增大,内外径及拉伸强度均减小;当牵引速率为350和420 m/min时,制得的中空纤维微孔膜结构与性能较好。

A series of polypropylene hollow fiber membranes was prepared by melt-spinning and coldstretching. The effects of drawn rate on properties of hollow fiber and membrane were studied in detail, such as crystallinity, elastic recovery rate, surface morphology, and so on. The results show that the crystallization behavior of hollow fiber is greatly influenced by drawn rate, and shish-kebab crystal is formed and uniformly distributed at higher drawn rate, which improves the hard elasticity. With the increase of the drawn rate, the surface structure of the hollow fiber membrane is changed, the porosity and water flux increased, and both the inner and outer diameter and tensile strength decrease. The hollow fiber membranes with excellent structure and properties were prepared when the drawn rate are 350 and 420 m/min respectivly.