摘要
本研究之目的為製備含甲基丙烯酸環氧丙酯交聯聚嗍碸薄膜以提升薄膜之滲透蒸發分離性能。利用光化學交聯法並加入適量交聯劑將單體交聯至聚嗍碸，研究探討紫外光照射、單體濃度、交聯劑及光起始劑對交聯薄膜之透過性能及薄膜特性之影響。以乾式成膜過程中因鑄膜液含交聯聚甲基丙烯酸環氧丙酯程度對聚嗍碸高分子成膜後
之型態及孔隙特性之影響，並探討其對滲透蒸發分離乙醇水混合液分離性能之影響。研究中可發現，紫外光照射時間及單體添加量較為顯著影響PGMA百分率，而交聯聚合物中環氧基的增加影響交聯薄膜對水分子吸附及膨潤特性，因而影響增加滲透蒸發選擇性及降低透過量。研究發現適量單體濃度增加可以有效增加PGMA百分率，而當單體添加過量則會產生自我聚合現象，導致鑄膜液相分離，成膜時溶液組成不均勻產生孔洞；因此適量的照射時間及單體濃度形成鑄膜液重要的因素。本研究也進一步對交聯膜材進行磺酸化反應，利用環氧基容易開環現象使磺酸基附著於交聯膜上，並探討磺酸化交聯膜對滲透蒸發分離乙醇水混合液分離性能之影響，研究中發現當交聯薄膜進一步磺酸對水分子吸附能力提升許多，使交聯薄膜更加親水而導致選擇性上升。最後將膜材製備為非對稱性薄膜，其探討對滲透蒸發之影響，研究中發現濕式成膜過程中鑄膜液溶液產生相分離，緻密層不易形成，無法阻隔乙醇水溶液，因而交聯薄膜選擇性不能有效提升。 ABSTRACT
The purpose of this investigation is to prepare a semi-IPN poly glycidyl methacrylate/polysulfone composite membrane for dehydration of water/ethanol solution by pervaporation. Utilizing semi-IPN technology with suitable dosage of cross linking agent, monomer concentration, radiated dosage, and initiator, the composite membranes were prepared and characterized the physical and chemical properties and their influences on the performance of pervaporation. In the first part of this investigation, the dry method was used to prepare the semi-IPN poly glycidyl methacrylate/polysulfone composite membrane. The effect of the PGMA content in the membranes on the morphology and hydrophilicity were investigated and the influences of the properties changes on the dehydration performance were also concerned by characteristics analysis. It was found that the radiated dosage and monomer concentration significantly dominated the content of PGMA in semi-IPN membranes and the increase in PGMA content also enhanced the water selectivity and swelling properties of composited membranes. Due to the IPN structure in polymer matrix, the selectivity of membranes increased and declined the permeation rate of permeate with increasing the degree of IPN. Thought the increase in monomer concentration enhanced the degree of IPN in the membrane, but the excessive monomer induced a homo-polymerization and lead to a decrease in the PGMA content in composite membranes. This homo-polymer induced the phase separation in the casting solution and further formed the micro-phase separation in the membrane formation. It is concluded that the optimum radiated dosage and monomer concentration in the semi-IPN solution are the key factors to prepare the homogeneous composite membranes. The second part of this investigation is to utilize the ring opening reaction with sulfuric acid to grafting the sulfuric group on the semi-IPN polymer. The sulfuric acid opened the epoxy group of PGMA to form the sulfonated PGMA. It was expected that the sulfuric group significantly enhanced the hydrophilic properties. The increase in the sulfuric group content in the composited membranes preferred the water selective property during the pervaporation and declined the water contact angle on the membrane surface. It is indicated that the hydrophilic properties of the polymer further increased by the sulfonation. The separation performance of pervaporation also showed the significantly improvement for dehydration by the semi-IPN modification on the polysulfone membranes. The third part of this study is to prepare the asymmetric membranes. It was found that the micro phase separation in the casting solution strongly declined the selectivity of IPN membranes. Base on the morphology observations and separation performance analysis, they were indicated that the polymer phase separation could not form a defect free skin layer and this factor dominated the decline of selectivity of composited membranes in the separation process.
