热处理对PVDF_PFSA中空纤维共混超滤膜结构及性能的影响

Vol.35No.42009-08华东理工大学学报(自然科学版)JournalofEastChinaUniversityofScienceandTechnology(NaturalScienceEdition)收稿日期:2008-10-13基金项目:国家/9730计划(2003CB615705);国家/十一五0科技支撑计划重大项目(2006BAE02A01)作者简介:袁国林(1981-),男,山东寿光人,博士研究生,主要从事膜分离技术的研究工作。通讯联系人:许振良,E-mail:chemxuzl@ecust.edu.cn文章编号:1006-3080(2009)04-0501-05热处理对PVDF-PFSA中空纤维共混超滤膜结构及性能的影响袁国林,许振良,魏永明(华东理工大学化学工程研究所,上海200237)摘要:以聚偏氟乙烯(PVDF)与全氟磺酸(PFSA)为共混膜材料,采用湿法纺丝制备了中空纤维共混超滤膜,考察了热处理温度与热处理时间对共混膜的渗透性能、膜结构、受热收缩率及机械性能的影响。结果表明:随热处理温度的升高,截留率先增加后降低,纯水通量先降低后升高,分别在80e时达到最大值与最小值,80e时PEG4000的截留率为95.0%,纯水通量为231L/(m2#h#MPa);膜的渗透性能随热处理时间变化而变化,在15min时出现极值;热处理使膜的支撑层结构发生转变,膜径向壁厚收缩率较大,轴向膜长度收缩率较小;热处理后中空纤维膜的断裂伸长率降低,而杨氏模量与断裂强度跟热处理后的膜支撑层结构密切相关;湿法纺制的PVDF-PFSA膜,经70e热处理15min后,制得截留分子量为4000的中空纤维共混超滤膜,其纯水通量为261L/(m2#h#MPa)。关键词:聚偏氟乙烯;全氟磺酸;共混;热处理中图分类号:TQ028.8文献标志码:AEffectofHea-tTreatmentonMorphologyandPerformanceofPVDF-PFSAHollowFiberUFBlendMembranesYUANGuo-lin,XUZhen-liang,WEIYong-ming(ChemicalEngineeringResearchCenter,EastChinaUniversityofScienceandTechnology,Shanghai200237,China)Abstract:Poly(vinylidenefluoride)(PVDF)-perfluorosulfonicacid(PFSA)hollowfiberblendmem-braneswerepreparedbywet-spinningmethod.Theeffectsoftheheat-treatmenttemperatureandtimeonthemorphology,permeationperformanceandmechanicalpropertiesofthemembraneswereinvestigated.Theresultsshowthatuponincreasingtheheat-treatmenttemperaturetheretentionratereachesamax-imumof95.0%forPEG4000at80bCwhilethefluxshowsaminimumof231L/(m2#h#MPa)forpurewateratthesameheat-treatmenttemperature.Theappropriateheat-treatmenttimewas15minforheat-treatmentat70e.Themorphologyofthemembraneswaschangedbyheat-treatmentasexaminedbyscanningelectronicmicroscopy(SEM).Thehollowfibermembranesareshrankaftertheheat-treatment,andtheaxialshrinkageratioofthemembraneissmallerthantheradialone.Theelongationatbreakde-clinesafterheat-treatment.TheYoungcsmodulusandthebreakstrengthofthehollowfibermembranescloselycorrelatetothemembranestructureafterheat-treatment.ThePVDF-PFSAhollowfiberblendmembranesheat-treatedfor15minat70bChaveacu-toffmolecularw