Preparation And Characterization Of The PPESK/PEI Hollow Fiber Membrane For Enriching Nitrogen

Using Poly(phthalazinone ether sulfone ketone)(PPESK) and polyetherimide(PEI) as the membrane material, N-methyl-2-pyrrolidinone(NMP) as solvent,γ-butyrolactone as nonsol-vent, silicone rabber as coating material, the PPESK/PEI hollow fiber membrane for enriching nitrogen was prepared and the performance of the PPESK/PEI hollow fiber membrane was studied.First, the structure and performance of the PPESK/PEI hollow fiber base membranes prepared based on the phase separation behavior has been researched. The effect of nonsol-vent contain, air gap of the dry/wet spinning process, temperature of casting solution, temperature of coagulant media and traction speed on the structure and performance of the PPESK/PEI hollow fiber base membranes has been systemically researched. The structure research and character analysis are made with SEM, gas permeability and separation coefficient. The results of experiment showed, an increase in nonsolvent contain can decrease the membrane separation performance and raise membrane permeation rate, the increase in air gap length in certain extent can improve membrane separation performance, the high temperature casting solution and low temperature coagulant media both can improve the membrane separation performance and decrease membrane permeation rate, the appropriate traction speed can improve the membrane separation performance but this change range is not very obvious. Summary from research, the preparation technology of membranes for enriching nitrogen is got.Second, using silicone rubber as coating material, the effect of silicone rubber concentration, coating vacuum, vacuum time, curing temperature, curing time and drying conditions on the structure and performance of the PPESK/PEI hollow fiber composite membranes coated silicone rubber has been systemically researched. The results of experiment showed, an increase in silicone rubber concentration can improve the coating quality but the too high concentration solution of silicone rubber can raise the thickness of coating and decrease permeation rate, the higher coating vacuum and longer vacuum time in certain extent both can improve membrane separation performance, the appropriate curing temperature and enough curing time were needed in the coating quality, the appropriate drying conditions can improve membrane performance and the coating quality. Summary from research, the preparation technology of silicone rubber coating is got. Finally, the PPESK/PEI hollow fiber composite membranes has been prepared by using the optimal process conditions and its separation coefficient and oxygen gas permeability is respectively 4.25 and 32.16 GPU. The influences of testing pressure and temperature to performance of the membranes were studied. The results showed that the effect of 0.8MPa testing pressure or testing temperature of 60℃on the performance of the membrane is uncons-picuous.