凝固浴条件对内衬型偏聚氟乙烯中空纤维膜结构与性能的影响

Effects of coagulation conditions on morphology and performance of braid reinforced poly(vinylidene fluoride) hollow fiber membranes

以聚对苯二甲酸乙二醇酯(PET)编织管为内衬支撑材料,采用非溶剂诱导相分离法和水平涂覆工艺制备内衬型聚偏氟乙烯(PVDF)中空纤维膜,通过改变凝固浴剂N,N-二甲基乙酰胺(DMAC)质量分数与温度等制膜工艺参数,改善用于膜生物反应器(MBR)中的内衬型PVDF中空纤维膜结构与性能。结果表明:膜分离层的孔径受DMAC质量分数与温度影响,降低DMAC质量分数或温度可以减小膜分离层孔径,膜通量减小;涂覆皮层的拉伸强度与爆破强度随凝固浴温度升高而增大,DMAC质量分数对它们的影响不显著;剥离强度与凝固浴温度、DMAC质量分数无关,保持在0.10 MPa左右。

To improve the performance of the reinforced hollow fiber membrane in the membrane bioreactor（ MBR）,poly（ vinylidene fluoride）（ PVDF） hollow fiber membranes reinforced by braid polybutylene terephthalate（ PET） tube were prepared by the process of non-solvent induced phase separation. Effects of the composition and temperature of coagulation bath on the morphology and performance of reinforced membrane were investigated. Results showed that membrane pore sizes were affected by N,N-dimethyl acetamide（ DMAC） mass fraction and temperature. Decreasing DMAC mass fraction or temperature of coagulation bath could reduce the membrane pore sizes and flux. The tensile strength of coating layer and membrane burst strength increased with increasing coagulation bath temperature,but DMAC mass fraction had unobvious influence. Peel strength around 0. 1 MPa was not affected by the coagulation temperature and DMAC mass fraction.