Study On Ployurethane/Polyacrylonitrile Blending Hollow Fiber Membrane Made By Melt Spinning-Drawing

In this paper, exhaustive studies on the mechanism of draw-interfacial phase separate micro-void, PAN/PU blending system, melt spinning technology of PAN/PU hollow fiber membrane, and the structure-property of PAN/PU hollow fiber membrane were fulfilled.The study on the mechanism of draw-interfacial phase separate micro-void was carried out. The results showed that it is impossible for "Island-Sea" structure non-compatible blend polymer to form interfacial phase separated micro-void after being drawn. The phase interface of blending polymer, the Poisson's ratio of blending component, the average particle diameter of disperse phase, the average particle size distribution of disperse phase, the concentration of disperse phase and the homogeneity of disperse phase affect the numbers and crosslinkage of interfacial phase separated micro-voidThe properties of PAN/PU blending polymer was also studied. The results showed that the PAN/PU blend system was not a thermodynamics compatibility one. The compatibility of PAN/PU blending polymer was very bad. The PAN/PU blending polymer is a "Island-Sea" structure system, and PAN content is disperse phase, and the particle diameter is from 0.5-4 u m when the concentration of PAN is from 0%-30%. The flowability of PAN/PU blending system become bad with the increase of the concentration of PAN.The melt-spinning technology of PAN/PU blending polymer was also studied. The PAN/PU hollow fibers were successfully fabricated when the spinning temperature was controlled from 190癈 to 200癈 and the rotate speed of screw less than 70r/min. The break strength and the extension at break of PAN/PU hollow fiber decreased with the increase of the concentration of PAN. PAN/PU hollow fibers possess excellent elastic recovery percentage.The study showed that the PAN/PU hollow fiber membranes were successfully fabricated the technic of draw-interfacial phase separate micro-void. The water flux ofPAN/PU hollow fiber membranes increased with the increase of draw ratio and concentration of PAN.The pressure memory effect and the temperature memory effect was also studied. The study showed that the memory effect of water flux of PAN/PU hollow fiber membranes was tightly related to interfacial phase micro-void.