_二次刮膜法制备处理石化污水聚偏氟乙烯复合膜

第37卷第7期现代化工July20172017年7月ModernChemicalIndustry二次刮膜法制备处理石化污水聚偏氟乙烯复合膜杨丽*，魏昕，杨永强，奚振宇(中国石化北京化工研究院，北京100013)摘要:研究了一次刮膜形成偶联层的涂覆液组成与刮膜厚度以及二次刮膜铸膜液的配方与成膜工艺，利用扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)等对制备的膜组成及结构进行了表征。首先通过聚合物共混相容性实验筛选出聚甲基丙烯酸甲酯(PMMA)作为支撑层聚酯无纺布与聚偏氟乙烯(PVDF)铸膜液之间的偶联层聚合物，确定一次刮膜涂覆液中PMMA的质量分数为12%，刮膜厚度为20μm;然后优化确定了二次刮膜铸膜液配方NMP/PVDF/PMMA/PVP质量比为74/16/4/6。经二次刮膜法制备的聚偏氟乙烯平板复合超滤膜机械强度高，抗反洗能力强，主体材料为PVDF，在0.1MPa条件下纯水通量稳定在628.1L/(h·m2)，接触角为53.7°，用于实际石化废水处理运行1个月膜平均产水通量约为68.3L/(h·m2)，产水浊度基本稳定在0.2～0.6NTU之间，膜表面污染物较少，抗污染能力强。关键词:聚偏氟乙烯;平板复合膜;二次刮膜;亲水性;增强型中图分类号:TQ028．8文献标志码:A文章编号:0253－4320(2017)07－0133－05DOI:10．16606/j．cnki．issn0253－4320．2017．07．031PreparationofPVDFcompositemembranebytwicecastingmembranemethodYANGLi*，WEIXin，YANGYong-qiang，XIZhen-yu(SINOPECBeijingＲesearchInstituteofChemicalIndustry，Beijing100013，China)Abstract:Compositionofcoatingsolutionandthicknessofcastingmembraneinformingacouplinglayerbythefirsttimecastingmembranearestudied，andthecastingsolutionformulaandmaking-membranetechniqueofthesecondtimecastingmembraneisalsostudied．Thecompositionandstructureofmembranearecharacterizedbyscanningelectronmicroscopy(SEM)，Xrayphotoelectronspectroscopy(XPS)，etc．Firstly，throughthecompatibilityexperimentsofpolymerblends，polymethylmethacrylate(PMMA)isscreenedoutasthecouplinglayerpolymerbetweenthesupportlayerpolyesternon-wovenfabricandpolyvinylidenefluoride(PVDF)castingsolution．ItisconfirmedthatthemassconcentrationofPMMAinthecoatingsolutionoffirsttimecastingmembraneis12%andthethicknessofcastingmembraneis20μm．ThenthesolutionformulaofthesecondtimecastingmembraneisoptimizedasNMP/PVDF/PMMA/PVP=74/16/4/6(masspercent)．ThePVDFflatcompositeultrafiltrationmembranepreparedbythetwicecastingmethodhasahighmechanicalstrengthandstronganti-backwashingability．WithPVDFasthebulkmaterial，itcanremainpurewaterfluxsteadyat628.1L·(h·m2)－1under0.1MPawhenthecontactangleis53.7°．Havingbeenusedintheactualoperationofpetrochemicalwastewatertreatmentforonemonth，theaveragemembranewaterfluxisabout68.3L·(h·m2)－1，andtheturbidityofprod