交联法制备聚酰亚胺中空纤维纳滤膜

Preparation of polyimide hollow fiber nanofiltration membranes by crosslinking

以不同分子量的聚乙烯亚胺(PEI)和小分子二元胺作为交联剂,对聚酰亚胺(PI)中空纤维膜进行化学交联来制备耐溶剂纳滤膜.考察了PEI分子量和交联时间对膜分离性能的影响.结果表明,膜分离性能随PEI分子量的增加变差,随交联时间的增加变好.用PEI600作为交联剂,交联时间为4h时,膜的纯水通量为8.3L/(m^2·h·MPa),对PEG1000的截留率为97.0%.3种小分子交联剂中,用乙二胺交联膜的分离性能较好,纯水通量为25.8L/(m^2·h·MPa),对PEG1000的截留率为82.6%.纳滤膜对药物三七总皂苷体系有良好的分离性能.

Polyimide hollow fiber membranes have been chemically crosslinked by polyethyleneimine(PEI)with different molecular weights and small molecule diamines in order to prepare nanofiltration(NF)membranes.The effects of the molecular weight of PEI and crosslinking time on the membrane separation performance were studied.It was found that membrane separation performance deteriorated with increasing molecular weight of PEI,while it improved with increasing crosslinking time.When PEI600 was used as the crosslinking agent and the crosslinking time was 4 h,the pure water permeance(PWP)and rejection of the membrane were 8.3 L/(m^2·h·MPa)and 97.0%respectively.When the separation performance of membranes crosslinked by small molecule diamines was compared,membranes crosslinked by ethylenediamine afforded the best separation performance with PWPof 25.8 L/(m^2·h·MPa)and rejection of 82.6%.In addition,the NF membranes showed good performance in the separation of total saponins in the panax notoginseng saponins(PNS)system.