發泡聚醯亞胺高分子(polyimide foams，PIF)是一種具有聚醯亞胺分子結構的耐高溫的多孔性材料。它有輕量化、耐熱性、耐化學藥品性、耐燃性及低熱導度等性，可以作為隔熱、吸音或阻燃材料，應用於火箭、飛彈、太空船、飛機、高速火車等高科技領域。
本研究將採用兩溶液一步驟(one pot)法來製備發泡聚醯亞胺高分子，其中第一溶液包含二酸酐(dianhydride)、DMF 溶劑、水、甲醇、界面活性 劑及觸媒，第二溶液是異氰酸酯(isocyanate)，發泡過程將在常溫進行。加入界面活性劑是為了提高發泡聚醯亞胺高分子的孔隙尺寸分佈的均勻性。加入觸媒是為了促進二酸酐和異氰酸酯的反應。另外，水含量及甲 醇含量，都會對孔洞結構及性能產生影響，所以本研究將透過改變水和甲醇的比例，合成出不同含水量和甲醇含量的發泡聚醯亞胺高分子，再將所合成出的發泡聚醯亞胺高分子進行結構鑑定與性質分析。
另外，本研究使用 4-氨基苯甲酸 (4-aminobenzoic acid, ABA) 對奈米
碳纖維 (carbon nanofibers, CNF) 進行表面改質，並將經改質之奈米碳纖
維摻入第一溶液中，以製備發泡聚醯亞胺/奈米碳纖維之複合材料，並另外分析其對發泡聚醯亞胺高分子之性能的影響。使用奈米碳纖維的目的為替代製程複雜而非常昂貴的奈米碳管(carbon nanotubes, CNT)。與純發泡聚醯亞胺高分子相比，發泡聚醯亞胺/奈米碳纖維之複合材料具有更佳的熱安定性與更高的機械強度。

We synthesized polyimide foams (PIF) by one-pot (two solution) method. The first solution contained dianhydride, DMF solvent, water, methanol, surfactant, and catalyst. The second solution was isocyanate, and the blowing process was carried out at room temperature. The surfactant was added to improve the uniformity of the cell size. The catalyst was added to promote the reaction of dianhydride and isocyanate. In addition, both water and methanol content will affect the microstructures and properties, so PIFs were synthesized using different amount of water and methanol.
In addition, 4-aminobenzoic acid (ABA) was used to modify carbon nanofibers (CNF), and CNF was added into the first solution to synthesize polyimide nanocomposite foams. Then, their effects on the properties of the PIFs were analyzed. The purpose of using CNFs was to replace carbon nanotubes (CNT), which are very expensive. Compared with pristine PIFs, the polyimide nanocomposite foams had better thermal stability and higher mechanical strength.

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