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采用干-湿法纺丝工艺制备PVDF/PVP共混中空纤维膜,利用红外分析技术和广角粉末衍射表征了膜组成和结晶性质,考察了液膜空气蒸发时间、铸膜液脱泡时间、拉伸速度、芯液温度等纺丝条件对膜的纯水通量、截留率、拉伸强度、断裂伸长率等性能的影响。结果表明,随芯液温度提高,膜纯水通量和截留率变化不大,但能显著提高拉伸强度和断裂伸长率;随着铸膜液脱泡时间和液膜在空气中蒸发时间的延长,膜纯水通量下降,截留率升高,拉伸强度和断裂伸长率增大;拉伸速度与膜拉伸强度和断裂伸长率呈正相关,在3.28 m.min-1时的膜纯水通量和截留率表现最佳。试验条件下得出的最优纺丝条件为:芯液温度60℃,静置脱泡48 h,蒸发时间2 s,拉伸速度3.28 m.min-1。
PVDF / PVP blend hollow fiber membranes were prepared by dry-wet spinning process. The composition and crystallization properties of PVDF / PVP blends were characterized by infrared spectroscopy and wide-angle powder diffraction. The effects of air evaporation time, Elongation speed, the temperature of the core liquid and other spinning conditions on membrane pure water flux, retention, tensile strength, elongation at break and other properties. The results show that with the increase of the temperature of the core liquid, the membrane pure water flux and retention rate change little, but can significantly improve the tensile strength and elongation at break; with the casting solution defoaming time and liquid film in the air evaporation time , The membrane pure water flux decreased, the retention rate increased, the tensile strength and elongation at break increased. The tensile speed was positively correlated with the tensile strength and elongation at break of the membrane. At 3.28 m.min-1 Membrane pure water flux and rejection performance best. The optimum spinning conditions obtained under the experimental conditions are as follows: the temperature of the core liquid is 60 ℃, the static degassing time is 48 h, the evaporation time is 2 s and the stretching speed is 3.28 m · min-1.