聚四氟乙烯複合膜之製備及其滲透蒸發效能研究

Study on the pervaporation performance of poly(tetrafluoroethylene) composite membranes

余鐘豪(Chung-Hao Yu)

指導教授 ： 劉英麟 ； 賴君義

中原大學/工學院/化學工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700425

摘要

本研究以氫氣電漿及臭氧處理技術對雙向延伸之多孔性鐵氟龍膜(bi-axially e-PTFE)表面上進行改質。經由氫氣電漿可以在 PTFE薄膜表面進行去氟化(defluorination)及氫化(hydrogenation)反應，導入C-H基團。C-H基團可以當作臭氧處理時之受體，與臭氧反應形成過氧化基(peroxide)。接著在導入過氧化基的PTFE膜表面上進行接枝聚合反應，使用苯乙烯磺酸鈉鹽(sodium 4-styrenesulfonate, NaSS) 為單體。並進一步使用鹽酸溶液處理e-PTFE-g-PNaSS薄膜，將苯乙烯磺酸鈉置換成苯乙烯磺酸基，標號為e-PTFE-g-PSSA。相較於單純使用氫氣電漿之e-PTFE薄膜，e-PTFE-g-PSSA具有更佳之親水性，而且沒有疏水性回復現象發生。
經由接枝聚苯乙烯磺酸基之e-PTFE表面，塗佈上含有交連劑γ-(glycidyloxypropyl)trimethoxysilane (GPTMS)之chitosan 溶液，製備出chitosan/e-PTFE複合膜，chitosan緻密層與改質後之e-PTFE基材間具有相當佳之貼合性，應用於滲透蒸發分離異丙醇水溶液具有高效能。對於分離進料70 wt%異丙醇水溶液70◦C下，透過量可達1730 g/m2 h，選擇比為775，而長時間之穩定性可維持45天。此複合膜分離廣範圍進料異丙醇濃度(40-90 wt%)亦具有良好之分離效能，透過水濃度均可以維持在99 wt%左右。
本研究亦以界面聚合法在改質後之e-PTFE表面製備polyamide/e-PTFE複合膜，應用於滲透蒸發分離異丙醇水溶液，對e-PTFE表面上導入不同官能基(-SO3H、-COOH、-NH2)所製備出之polyamide/e-PTFE複合薄膜之滲透蒸發操作穩定性做探討。研究結果顯示當導入胺基(-NH2)於e-PTFE表面上時，胺基能於界面聚合層之醯氯官能基反應形成共價鍵結，所製備出之polyamide/e-PTFE複合薄膜滲透蒸發操作穩定性最佳。

關鍵字

聚四氟乙烯 ； 界面聚合 ； 電漿 ； 幾丁聚醣 ； 滲透蒸發

並列摘要

In this study, hydrogen plasma and ozone treatment technology were applied to modify the expended poly(tetrafluoroethylene) (e-PTFE) film surface. C–H groups were introduced to the surface of PTFE films through defluorination and hydrogenation reactions under hydrogen plasma treatment. The C–H groups then served as ozone accessible sites to form peroxide groups under ozone treatment. Grafting polymerization initiating from the peroxide groups was performed on the e-PTFE film surface with using sodium 4-styrenesulfonate (NaSS) as monomer. Further treating e-PTFE-g-PNaSS with a hydrochloride aqueous solution converted sodium styrenesulfonate groups to styrene sulfuric acid coded as e-PTFE-g-PSSA. Compared with only H2 plasma treatment e-PTFE membrane, e-PTFE-g-PSSA membranes have more hydrophilicity, and no hydrophobic recovery phenomena occurred.
Chitosan/e-PTFE composite membranes were prepared from casting a γ-(glycidyloxypropyl)trimethoxysilane (GPTMS)-containing chitosan solution on poly(styrene sulfuric acid) grafted expended poly(tetrafluoroethylene) film surface. The adhesion between the chitosan skin layer and the modified PTFE substrate was pretty good to warrant the high performance of chitosan/e-PTFE composite membranes using in pervaporation dehydration processes on isopropanol aqueous solution. The chitosan/e-PTFE membrane exhibited a permeation flux of 1730 g/m2h and a separation factor of 775 at 70 ◦C on pervaporation dehydration of a 70 wt% isopropanol aqueous solution, and survived after a long-term operation test in 45 days. The membrane also show good performance in wide feed isopropanol aqueous solution concentration (40-90 wt%), the water concentration of permeate still can maintain around 99 wt%.
This study also used interfacial polymerization technology to prepare polyamide/e-PTFE composite membranes on modified e-PTFE membranes surface using in pervaporation dehydration processes on isopropanol aqueous solution. Investigated the polyamide/e-PTFE composite membranes stability during pervaporation process, those composite membranes were prepared by introduced three different function groups(-SO3H、-COOH、-NH2) on e-PTFE membranes surface. The result showed that when introduced amine function group on e-PTFE membranes surface, the polyamide/e-PTFE composite membranes had best stability owing to the amine group could reacted with interfacial polymerization layer formed covalent bond.

並列關鍵字

interfacial polymerization ； pervaporation ； poly(tetrafluoroethylene) ； chitosan ； plasma

參考文獻

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