六亚甲基二异氰酸酯(HDI)交联壳聚糖与三甲基-烯氯化铵接枝共聚物/聚丙烯腈复合纳滤膜的研究  

Study on composite nanofiltration membrane from graft copolymer of trimethylallyl ammonium chloride onto chitosan/poly(acrylonitrile)(PAN) by hexamethylene diisocyanate(HDI)cross-linking

作　　者：黄瑞华[1] 陈国华[1] 孙红伟[1] 高从[1] 

机构地区：[1]中国海洋大学化学化工学院,山东青岛266003

出　　处：《功能材料》2007年第2期308-312,共5页Journal of Functional Materials

基　　金：国家重点基础研究发展计划(973计划)资助项目(2003CB615706)

摘　　要：以壳聚糖与三甲基-烯氯化铵共聚物的水溶液为铸膜液,涂敷在聚丙烯腈超滤膜上,以六亚甲基二异氰酸酯为交联剂,制备了壳聚糖与三甲基一烯基氯化铵共聚物复合阳离子型纳滤膜。着重讨论了交联剂浓度、交联时间、干燥时间等因素的影响,采用单因素实验法确定了最佳的制膜条件:以0.75%(质量分数)的壳聚糖与三甲基-烯氯化铵共聚物水溶液为铸膜液,在50℃下干燥2h。在乙醇、HDI的质量比为50∶0.32交联体系中,50℃水浴浸泡交联21h,50℃下热处30min。通过电镜扫描对膜结构进行观察。膜的截留分子量大约为900Da。并且,对该复合膜的性能进行了测试,分别探索了操作压力、料液浓度、料液类型等因素与膜性能的关系。在20℃,流速为30L/h,操作压力为1.2MPa时,对2000mg/L MgCl2、NaCl、MgSO4、CaCl2、Na2SO4、KCl、K2SO4的截留率分别为95.6%、66.4%、80.8%、95.4%、30.7%、53.7%、23.8%;通量分别为6.73、7.35、6.43、6.73、6.12、6.12、6.43L/(h.m-2)。对不同类型无机盐的截留顺序为MgCl2≈CaCl2>MgSO4>NaCl>KCl>Na2SO4>K2SO4,呈现阳离子型复合纳滤膜的截留特征。流动电位曲线进一步说明了该复合膜的荷正电性,其电压渗系数β为6.8mV/MPa。A novel positively charged composite NF membrane is prepared by casting aq. graft copolymer of trimethylallyl ammonium chloride onto chitosan on a PAN UF membrane, subsequently cross-linked with hexamethylene diisocyanate （HDI）. The effect of membrane preparation conditions such as HDI concentration, curing time, cross-linking temperature, etc on membrane properties is studied. The optimal condition is obtained by single--factor experiment as follows： 0.75wt% GCTACC , cured at 50℃ for 2h, cross-linked at 50℃ for 21h with HDI/ethanol （50/0.32 w/w）, heated for 30min at 50℃ finally. The structure of the NF membrane is characterized by scanning electron microscopy, its molecular weight cut-off is obtained at 900Da or so. In an addition, the effect of the operation conditions such as operating pressure, feed concentration, type of feed, etc on membrane performance is also investigated. At 20℃ and 30L/h of cycling flow and 1.2MPa of operating pressure, the rejections to 2000mg/L MgCI2, NaCI, MgSO4 ,CaCI2, Na2SO4, KCI and K2SO4 solutions are 95.6%, 66.4%, 80.8%, 95.4%, 30.7%, 53.7% and 23.8%, respectively, with the flux of 6.73, 7.35, 6.43, 6.73, 6.12, 6.12 and 6.43L/（h·m^-2）, respectively. The order of rejection to different salt solutions follows the deceasing of MgCl2, CaCl2, MgSO4, NaCI, KCl, Na2 SO4 and K2SO4, revealing the characteristic of positively charged NF membrane. Besides, the curve about the streaming potential illuminates the positively charged characteristic of this membrane further, with a pressure osmobic coefficient of 6.8mV/MPa.

关 键 词：壳聚糖与三甲基-烯基氯化铵共聚物 六亚甲基二异氰酸酯 阳离子型复合纳滤膜 膜制备 

分 类 号：TQ028.8[化学工程]