本研究之高性能的質子半透膜的薄膜材料設計概念主要建構semi-IPN(interpenetrating polymer network)系統的結構之上，亦即將所得到的具高支鏈結構(hyper branch architecture)雙馬來醯亞胺寡合物(bismaleimide oligomer;mBMI)導入磺酸化聚二醚酮高分子(sPEEK)中，並進行雙馬來醯亞胺寡合物的加熱化學交聯（thermochemical crosslinking），築構成半互穿網路聚合物?semi-IPN(interpenetrating polymer network)?結構。本研究顯示，mBMI在180度高溫經過不同時間處理後可以形成較完整的交聯結構，因此複合高分子半透膜不僅展現較好的熱穩定性外，而且mBMI樹枝結構狀的存在可以有效降低半透膜的膨潤性，還能有效的提高薄膜的保水能力，使得這些複合薄膜在較高溫度下，還得以維持導電度。含有不同濃度的 mBMI(98)(mBMI:BMI=98:2)的高分子薄膜在高溫下其導電度仍維持一定水平，不因為高溫(<100oC)失散水分使導電度急速下降。但利用變溫導電度發現mBMI(30)會在超過100oC還能維持導電度。而純的sPEEK在超過85oC，導電度則會往下掉落，而且薄膜會因為高溫吸水而漸漸被溶解掉。 sPEEK在高溫(180oC)之下，會有些結構上的變化，苯環之間的π-π stacking和磺酸根彼此互相交聯。在加入了mBMI，在高溫180oC之下會產生熱交聯現象，mBMI也有些π-π stacking作用力。這兩者不同hyperbranch程度的高分子因為結構上的差異，對於sPEEK也會有不同作用力，使得薄膜系統的離子導電度不同。藉由water uptake、AC impendence、IEC、NMR、FL、DSC、TGA、DMA、methanol permeability、SEM去分析sPEEK/mBMI這系統的一些特性。 要瞭解薄膜水分的特性，由控制濕度儀和AC impendence結合在一起，控制濕度和導電度的關係。從吸附水分實驗知道sPEEK/mBMI的吸附水分的能力是否為高溫保住水分的關鍵。從定溫變濕度實驗顯示是否能在低濕度傳導質子。從定濕度變溫實驗可以瞭解薄膜的活化能，不同濕度的質子傳導的難易度。 此外，固態NMR的數據也顯示，複合薄膜在高溫下至少還有2~3個水分子被保留，而這些水分子是存在於sPEEK的磺酸根和mBMI分子之間並用來傳遞質子。而形成hyperbranch結構愈完整，愈有利於高溫時的薄膜保水性。 Present work disclosed a new design of proton exchange membrane for fuel cell employing the semi-IPN (interpenetrating network) structure established between hyper branched bismaleimide oligomer and the Sulfonated poly(ether ether ketones) sPEEKs. Numerous advantages in operating the fuel cell at elevated temperature can be identified; however the membrane proton conductivity decreases substantially due to the loss of water at temperature near 100 oC. The semi-IPN membrane forms highly durable membrane with fair high temperature conductivity. Variable temperature proton conductivity over broad temperature range (20oC to 140oC) under different moisture conditions shows the semi-IPN structure is more effective in retaining water at these temperatures and successfully preserved the proton conductivity. The physical and conductivity properties of the semi-IPN membrane depend on (a) the degree of hyper branch and content of the mBMI in the membranes, (b) the conditions of the temperature program during curing the membrane. Present study examines in detail the correlation between the semi-IPN micro structure and these physical properties especially the proton conductivity. In addition, detailed proton conducting mechanisms in these semi-IPN structured membranes will be demonstrated by solid state NMR. In order to develops an excellent proton conducting membrane, we proposed a semi-IPN (interpenetrating network) structure established between hyper branched architecture of bismaleimide oligomer and the architecture matrix sulfonated poly(ether ether ketone) (sPEEK). By using an in-situ polymerization scheme, where bismaleimide oligomers and bismaleimide monomers forms IPN structure within the sPEEK polymer matrix, the thermal polymerization of the bismaleimide oligomers and the film formation can be performed simultaneously. With increasing the reaction temperature and time, BMI monomer and mBMI (modified Bismaleimide oligomers) forms a more complete hyper branched network structure within the polymer solution. As a results, sPEEK polymer chain interpenetrates into hyper branch structure to form a semi-IPN structure. The physical and ion conductivity properties of the semi-IPN membrane depend on (a) the degree of hyper branch and content of the mBMI in the membranes, and (b) the conditions of the temperature program during casting membrane. Proton conducting mechanisms in the IPN membranes is also important. The methanol permeability of sPEEK/mBMI membrane is found to be effectively reduced in high concentration 50vol% methanol solution compared with Nafion 117 membrane. And the proton conductivity of most membranes is above 1.43×10-2 S/cm at ambient temperatures
