聚间苯二甲酰间苯二胺超滤膜的制备与性能研究

Preparation and performance of poly(m-phenylene isophthalamide)ultrafiltration membranes

以聚间苯二甲酰间苯二胺(PMIA)为膜材料,N,N-二甲基乙酰胺(DMAc)为溶剂,分别以氯化锂(LiCl)、聚乙烯吡咯烷酮(PVP)、聚乙二醇(PEG)为添加剂,采用相转化法制备PMIA超滤膜,研究了聚合物浓度、添加剂的种类对铸膜液体系及膜结构和性能的影响.结果表明,随着PMIA、LiCl、PVP和PEG含量的增加,铸膜液的黏度增加;随着PMIA、PVP和PEG含量的增加,铸膜液的热力学稳定性降低,但是LiCl的加入使铸膜液的热力学稳定性提升.通过对膜结构和性能的分析可知,随着PMIA、LiCl和PVP含量的增加,膜的孔隙率和纯水通量降低,而PEG的增加则使膜的孔隙率和纯水通量先增加后降低,当PMIA质量分数为12%,PEG质量分数为6%时,膜纯水通量高达707.43L/(m2·h),所有膜对BSA都具有较高的截留率,均在99%以上.

Poly(m-phenylene isophthalamide)(PMIA)ultrafiltration membranes were prepared by L S phase inversion method by using PMIA as membrane material,N,N-dimethylacetamide(DMAc)as solvent,lithium chloride(LiCl),polyvinyl pyrrolidone(PVP)and polyethylene glycol(PEG)as additives,The effects of polymer concentration and additive type on casting solution systems,membrane structure and performance were investigated.The results showed that the viscosity of the casting solution increased with the increasing of PMIA,LiCl,PVP and PEG content;and the thermodynamic stability of the casting solution decreased with the increasing of PMIA,PVP,and PEG content,but the addition of LiCl resulted in the thermodynamic stability of the casting solution increasing.Through the analysis of the structure and properties of the membrane,the membranes porosity and pure water flux decreased with the increasing of the concent of PMIA,LiCl and PVP,while the increasing of PEG addition caused that porosity and pure water flux increased and then decreased,a high pure water flux of 707.43 L/(m 2·h)was achieved when the PMIA content was 12%and the PEG content was 6%,and all the PMIA membranes showed a good rejection for BSA as high as 99%.