凝固浴温度对PVDF/PES-C共混膜结构及性能的影响

Effect of coagulation temperature on structure and property of PVDF/PES-C blend membrane

摘要:

以邻苯二甲酸二丁酯和N,N-二甲基乙酰胺为混合稀释剂，采用热致相分离法（TIPS）制备了聚偏氟乙烯（PVDF）/酚酞型聚醚砜（PES-C）共混膜，考察了不同凝固浴温度对膜结构和性能的影响。采用扫描电镜观察了膜的结构，测试了膜的纯水通量。运用DSC和XRD方法检测了膜的结晶性能。将制备的膜在膜生物反应器（MBR）中运行测试了膜的污水通量和出水指标。随凝固浴温度的升高，共混膜的最高熔融温度上升，膜中α晶型的含量增加。在凝固浴温度为25℃时，膜形成了较为致密的皮层结构和较为疏松的支撑层结构，此时共混膜的纯水通量和污水通量达到最大值，且MBR出水COD和NH4 -N含量达到排放要求。

Abstract:

PVDF/ PES-C blend membranes were prepared via TIPS method by using DBP and DMAc as mixed diluents. The effect of coagulation temperature on membrane structure and property were examined. The membrane structure was observed through SEM and pure water flux was tested. The crystal property of membrane was examined with DSC and XRD method. The waste water treatment property was also checked by using the membrane in MBR. Both the highest melting temperature and the content of α crystal form in blend membrane increased along with the increase of coagulation temperature. A thinner skin layer and a porous support layer formed when the coagulation temperature was 25℃. At this temperature, the pure water flux and sewage flux had a maximum value and the MBR remove ratio of COD and NH4 -N reached the discharge standard.