混合稀释剂制备PVDF微孔膜的结构与性能研究

Study on Structures and Properties of PVDF Membrane Prepared By Mixed Diluents

以邻苯二甲酸二甲酯(DMP)和N,N-二甲基乙酰胺(DMAc)作为混合稀释剂,采用复合热致相分离法制备聚偏氟乙烯(PVDF)微孔膜,并用扫描电镜、差示扫描量热分析仪、拉伸压缩材料试验机等测试仪器对微孔膜结构和性能进行了研究。结果表明:随着PVDF含量增加,体系的结晶度下降;随着混合稀释剂中DMP含量增加,膜强度先增大后减小,而水通量增加,截留率减小;冷却速率对孔隙率影响不大,但冷却速率减小,水通量增加,而截留率下降;DMAc与DMP质量比为1/2时,膜强度以及水通量均比单纯采用DMP做稀释剂时的好,前者的水通量达247 L/h.m2,比后者的增加了28%。

The polyvinylidene fluoride （PVDF） membrane was prepared via complex thermally induced phase separation （C-TIPS） method using DMP/DMAc mixture as the diluent. With the analysis of SEM, DSC and tensile compression testing, the structures and properties of membrane was studied. The results showed that with the PVDF content increasing, the crystallinity system decreased. With the increase of content of DMP in the mixed diluents, the strength of the membrane increased first, and then decreased, while the water flux increased, and BAS interception capacity decreased. The cooling rate had little effect on porosity of the membrane, but with the cooling rate decreasing, the water flux increased, while the BAS interception capacity decreased. While the ratio of DMAc and DMP was 1/2, the strength of membrane and water flux was obviously improved comparing with that only using DMP as diluents. The water flux reached to 247 L/h · m^2 , increasing by 28% than the latter.