Preparation Of PVDF/TPU Blend Hollow Fiber Membrane

The technology of membrane wastewater treatment has been regarded as a hotspot by many researchers currently, but it is seriously obstructed its development because of the shortcoming of its lower output, easier to be polluted, and higher price., this article prepared a new blends hollow fiber membrane which has big water flux, high intension and lower price. In terms of originality and theoretical value, the following aspects are among the most telling:1.Originally, the compatibility of PVDF andTPU was predicted and analyzed by means of calculation ofΔHm, FTIR, Differential Scanning Calorimetry method, and Solution Viscosity method respectively. It was demonstrated that PVDF/TPU possesses partial compatibility which is depended on and influenced by blend ratio, concentration of polymers in solution, temperature, etc.. The compatibility in PVDF-rich phase is greater than in PVDF-poor phase.2. The PVDF/TPU nonsolvents systems and which was prepared with for hollow-fiber membrane was given. It was presented the mechanism of the phrase inversion methods and the peculiarity of hollow-fiber membrane preparation. The effects of composition of coagulation on the properties of blend hollow-fiber membranes were discussed in the paper. And it tested the pore structure porosity of PCDF/TPU hollow-fiber membrane by scanning electron microscope. It was estimated the performance of blend membranes by measuring the flux and the BSA solute rejection.3.Based on large amount of studies of the influence of the technologcial conditions on the structures and properties of hollow fiber membrane such as gelation bath temperature, the concentration of solvent in gelation bath, the flux of core fluid, the concentration of core fluid ,the height of dry spinning systematically, the results showed that it is suitable technologcial conditions of casting solution that 20%DMAC used as coagulation bath and temperature of coagulation bath was 30°C and inner solution concentration was 0% and dry length was 14mm.Under this condition, the best performance of membrane was produced with the intention of prepared membrane reached 45.6KN/cm~2, the tensility reached 1.63, water flux reached 775. 6L/m~2·h, and retention ratio reached 53. 3%.4. It was studied the stability, compression resistance and impact of shock loading of PCDF/TPU hollow-fiber membrane. And the paper forecasted the development prospect of hollow-fiber membranes to treat the water. In the causticity bearing test, putting the membrane in the solution of H2SO4 and NaOH, it was showed that the membrane had great ability in bearing acid and alkali, and can run in the solution of broad pH range.