全氟磺酸改性聚乙烯醇渗透汽化膜分离乙酸乙酯-水溶液

Pervaporation Separation of Ethyl Acetate-Water Solutions through the Polyvinyl Alcohol Membranes Modified by Perfluorosulfonic Acid

以聚乙烯醇(PVA)为原材料,全氟磺酸(PFSA)为共混改性材料,以聚丙烯腈(PAN)中空纤维超滤膜为底膜制备了PVA/PAN、PVA-PFSA/PAN复合膜,并用于乙酸乙酯脱水。考察了共混涂膜液中PVA/PFSA配比,交联剂酒石酸(Tac)用量以及原料液温度与浓度对PVA/PAN、PVA-PFSA/PAN复合膜分离性能的影响。实验结果表明,Tac交联的PVA/PAN、PVA-PFSA/PAN复合膜均对水具有较好的分离选择性。共混涂膜液中PVA/PFSA质量比为1/1、Tac/PVA质量比为1/5时所制备的PVA-PFSA/PAN复合膜渗透汽化分离性能最佳。40℃下此复合膜用于分离98%(wt)的乙酸乙酯水溶液时,其渗透通量和分离因子分别为81.1g·m-2·h-1和1890。同样条件下,与交联PVA/PAN复合膜相比,交联PVA-PFSA/PAN复合膜的渗透通量显著提高。

Using polyvinyl alcohol （PVA） as coating material, perfluorosulfonic acid （PFSA） as modifier and the hollow fiber ultrafiltration membrane of polyacrylonitrile （PAN） as support layer, the PVA/PAN and PVA-PFSA/PAN composite pervaporation membranes used for the dehydration of ethyl acetate （t^Ac）-water solution were prepared by impregnation method, respectively. The effects of the mass ratio of PVA/PFSA in coating solution, the dosage of the cross-linking agent Tac （tartaric acid）, the dehydration temperature and the EAc concentration of the dehydrated solution on the pervaporation performance of prepared PEA/PAN and PVA-PFSA/PAN composite membranes were investigated The results show that both the PVA/PAN and PVA-PFSA/PAN composite membranes exhibit good water separation properties. The PVA-PFSA/PAN composite membrane prepared has the best pervaporation performance when the mass ratios of PVA/PFSA and Tac/PVA in coating solution are 1/1 and 1/5, respectively. When the PVA-PFSA/PAN composite membrane was used tbr the separation of 98%（wt） EAc aqueous solution at 40℃, the total permeation flux （J） reaches 81.1 g·m^-2·h^-1, and the separation factor （α） is 1890; Under the same dehydration conditions, the permeation flux of PVA-PFSA/PAN composite membrane is remarkably higher than that of PVA/PAN composite membrane.