PDMAEMA改性PEBA/PSF复合膜的制备及其渗透汽化分离性能

Preparation and pervaporation performance of PDMAEMA modified PEBA/PSF composite membranes

为了改进聚醚嵌段酰胺(PEBA)/聚砜(PSF)膜的透水性,采用共混聚甲基丙烯酸-N,N-二甲氨基乙酯(PDMAEMA)的方法,通过季胺化交联反应在膜内固定水溶性的PDMAEMA,使其在使用中不至于溶出,制备出PDMAEMA-PEBA/PSF复合膜,并用于乙二醇脱水,考察了不同共混含量对膜渗透汽化脱水性能的影响,通过析因设计探究了交联条件(交联剂种类、交联剂浓度、交联时间)对膜渗透选择性能的影响,遴选出能够使共混膜具有良好渗透选择性能的交联条件,并对改性后膜的表面性质进行了研究.结果表明:当聚合物质量浓度为10 g/L、PDMAEMA质量分数为15%~25%时,共混膜与PEBA/PSF膜相比,水通量提高了约80%,水/乙二醇分离因子提高了约40%;共混改性后膜表面亲水性增加,平均粗糙度增加了约120%,纯水接触角下降了约7°.

In order to improve the water permeability of polyether block amide（PEBA）/polysulfone（PSF） membrane, the method of blended poly-N,N-dimethylaminoethyl methacrylate（PDMAEMA） was used. PDMAEMA-PEBA/PSF composite membrane was prepared by quaternization crosslinking reaction to fix water soluble PDMAEMA in the membrane to avoid dissolution, and the membrane was used for ethylene glycol dehydration. The influence of blending content on pervaporation dehydration performance of the membrane was investigated. The effects of cross-linking conditions（including species of cross-linking agent, concentration of cross-linking agent, and crosslinking time） on the membrane permselectivity were explored by factorial design. A suitable cross-linking condition for making the blended membrane with a good permselectivity was selected. And the surface properties of the modified membrane were studied. The results showed that when the polymer content was 10 g/L and the content of PDMAEMA was 15%-25%, compared with PEBA/PSF membrane, the water flux increased by about80%, water/glycol separation factor increased by about 40%. The surface hydrophilicity of modified blended membrane increaseed, the average roughness increased by about 120%, the contact angle of pure water decreased by about 7°.