界面聚合法製備聚醯胺/聚丙烯娃X薄膜應用於滲透蒸發分離程序之研究

Study on polyamide/PAN composite membrane by interfacial polymerization for pervaporation for pervaporation

許昭仁(Chao-Jen Hsu)

指導教授 ： 賴君義

中原大學/工學院/化學工程學系/碩士(2006年)

https://doi.org/10.6840/cycu200600509

摘要

為了改善聚醯胺薄膜低透過量的缺點，本研究利用不同結構的二胺溶於水中(水相溶液)與trimesoyl chloride (TMC)溶於toluene(有機相溶液)，於改質過之聚丙烯(modified polyacrylonitrile, mPAN)基材膜的表面上進行界面聚合反應製備polyamide/mPAN複合薄膜，並應用於滲透蒸發分離醇類水溶液。探討二胺種類、水相與有機相濃度、水相處理時間、聚合時間與進料濃度及溫度對滲透蒸發分離效能的影響，並利用SEM、ATR-FTIR、contact angle與AFM分析複合薄膜表面聚合層的性質與型態。研究發現，經由界面聚合所形成之聚合層在靠近基材位置處有較為緻密的結構，而遠離基材之聚合層結構則較為鬆散。利用EDA/H2O與TMC/toluene進行界面聚合所製備之聚醯胺複合薄膜，隨著水相與有機相濃度及聚合時間增加，整體聚合層厚度增厚，導致透過阻力增加，當有機相濃度增加達1 wt%時，因TMC部分的-COCl基團水解成-COOH，導致複合薄膜聚合層親水性增加，使透過量與透過水濃度皆呈現最高效能。另外，當進料異丙醇濃度增加時，其透過量與透過水濃度皆呈現下降之趨勢；而隨著進料溫度上升時，其透過量過水濃度皆呈現上升之趨勢。研究中發現在5 wt% EDA水溶液中處理30min，於1 wt% TMC有機溶液聚合3min，所製得之複合薄膜在70℃下進行90 wt%異丙醇水溶液之分離有最佳的分離效能，其透過量為350 g/m2-h，透過水濃度為96.5 wt% 。

關鍵字

複合薄膜 ； 界面聚合 ； 滲透蒸發

並列摘要

In order to improve the permeation rate of polyamide membrane, the polyamide thin-film composite membranes were prepared by interfacial polymerization of various diamines with trimesoyl chloride (TMC) onto the surface of the modified asymmetric polyacrylonitrile (mPAN) membrane for pervaporation separation of aqueous alcohol solution. Effect of diamine types, concentration of aqueous phase and organic phase, immersion time of aqueous phase, polymerization time, and concentration and temperature of feed on the pervaporation performances through polyamide/mPAN composite membranes were investigated. SEM, ATR-FTIR, water contact angle and AFM were used to characterize surface properties and morphologies of the polyamide active layers of the composite membranes. It was found that the structure of the polyamide active layer by interfacial polymerization near the support was denser, and that far away from the support was looser. For the EDA-TMC/mPAN composite membrane, the entire thickness of active layer increases with increasing the concentration of aqueous and organic phases, TMC, and the polymerization time, as resulted in increasing the permeation resistance. When the concentration of TMC solution increased up to 1 wt%, the hydrophilic property of the polyamide active layer increased. It was because that the unreacted -COCl groups of TMC were hydrolyzed to -COOH, as resulted in both highest permeate rate and water concentration in permeate for separation of 90 wt% aqueous isopropanol solution. In addition, it was also found that the increase of isopropanol concentration in feed resulted in decreasing the permeation rate and water concentration in permeate. While the permeation rate and water concentration in permeate increased with increasing the feed solution temperature. The polyamide/mPAN composite membrane prepared by immersing in 5 wt% aqueous EDA solution for 30min, and then contacting with 1 wt% TMC for 3min have the best pervaporation performance. For pervaporation separation of 90 wt% aqueous isopropanol solution at 70℃, that is, the permeation rate and water concentration in permeate are 350 g/m2-h and 96.5 wt% respectively.

並列關鍵字

interfacial polymerization ； pervaporation ； composite membrane

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