界面预湿处理对异质增强型PVDF中空纤维膜结构与性能的影响  

Effect of Interface Pre-wetting on Performance of Heterogeneous Reinforced Polyvinylidene Fluoride Hollow Fiber Membranes

作　　者：范智丽 肖长发[1] 刘海亮[1] 胡晓宇[1] 环国兰[1] 

机构地区：[1]天津工业大学中空纤维膜材料与膜过程省部共建国家重点实验室培育基地,天津300387

出　　处：《高分子学报》2014年第11期1508-1516,共9页Acta Polymerica Sinica

基　　金：国家重点基础研究发展计划(973计划;项目号2012CB722706);国家高技术研究发展计划(863计划;项目号2012AA03A603);国家自然科学基金(基金号21274109);长江学者和创新团队发展计划资助(项目号IRT13084);天津市应用基础与前沿技术研究计划(重点项目)(项目号14JCZDJC37300)资助

摘　　要：以熔融纺丝聚氯乙烯(PVC)中空纤维多孔膜为增强体,聚偏氟乙烯(PVDF)为成膜聚合物,聚乙烯吡咯烷酮(PVP)为添加剂,N,N-二甲基乙酰胺(DMAc)为溶剂,配置铸膜液,采用同心圆牵引-涂覆法制备了异质增强型PVDF中空纤维膜.制备过程中,采用预湿溶液对增强体基膜表面进行预处理,研究了预湿溶液组成及含量对异质增强型PVDF中空纤维膜结构与性能的影响.结果表明,未经预湿处理的异质增强型PVDF中空纤维膜具有较厚的致密界面层;预湿溶液可对基膜表面孔起到保护作用,使异质增强型PVDF中空纤维膜的界面层变薄或形成多孔界面层,有益于改善增强型PVDF中空纤维膜的通透性能;与二甲基乙酰胺(DMAc)水溶液相比,以乙醇水溶液为预湿溶液所得异质增强型PVDF中空纤维膜的性能较优;当预湿液中乙醇含量为60 wt%时,所得增强型PVDF中空纤维膜的渗透性能较优,拉伸强度可达8.61 MPa.Heterogeneous reinforced （HR） polywinylidene fluoride （PVDF） hollow fiber membranes consisting of polyvinyl chloride （PVC） matrix membrane and PVDF coating layer were fabricated via concentric circles coating process. The polyvinyl chloride （PVC） matrix membrane with macroporous structure was prepared by melt-spinning method. While the coating layer was obtained by non-solvent induced phase separation method with PVDF as the polymer matrix, dimethylacetamide （DMAc） as the solvent, and polyvinylpyrrolidone （PVP） as the pore-forming agent. During the coating process,high concentration DMAc of polymer solutions could infiltrate into the surface pore of PVC hollow fiber membranes due to the effect of capillary force. Interface layer was formed between the coating layer and the matrix membrane of the HR PVDF hollow fiber membranes with compact structure. Therefore, pre-wetting solutions were used for the pretreatment of PVC matrix membranes before the coating process. The influences of pre-wetting solutions on structure and performance of HR membranes were investigated. The results showed that the interface layer of HR membranes without pre-wetting solutions was thick and dense. Because of the protection of pre-wetting solutions to surface pores of matrix membrane,the interface layer of HR membranes was thin and porous. The performance of HR membranes with pre-wetting solutions of ethanol and ethanol aqueous solutions were better than that of the DMAc aqueous solutions. The optimal permeability of HR membranes was obtained as the ethanol concentration of pre-wetting solutions reached to 60 wt%. The tensile strength of HR PVDF hollow fiber membrane was nearly 9 MPa. The results also showed that the interface adhesion between reinforcement and separation surface had a good combination in the range of 40% elongation.

关 键 词：聚偏氟乙烯 异质增强 中空纤维膜 预湿处理 界面层 

分 类 号：O631.1[理学—高分子化学]