在軟性電子產業中產品的開發已逐步朝向可撓曲且高透明的方向進展，像是軟性印刷電路板(flexible printed circuit, FPC)、可撓式顯示器(flexible display)以及軟性太陽能電池(flexible solar cell)基板等，因此軟質塑膠基板材料的使用漸趨普遍，然而材料本身也需具備足夠的熱穩定性與機械強度，以便於後續的製程加工，聚醯亞胺(polyimides, PI)高分子材料其本身擁有優越的耐熱性和機電性能，因此可運用於軟質塑膠基板的製作材料。
然而聚醯亞胺高分子材料因分子中含共軛苯環結構使其形成電荷轉移錯合體 (charge transfer complex)，影響其薄膜產生黃色或是紅棕色的色澤，降低其透明性也限制了在工業上的應用，此外，聚醯亞胺高分子材料因剛硬的分子鏈結構使其溶解度有限，減低了可加工性，因此為改進聚醯亞胺高分子材料於應用上的不足與缺陷，目前已有相當多的文獻研究致力於提出改良方法並且開發出不同種類的透明無色聚醯亞胺高分子材料。
隨著環保意識的抬頭以及環保法規的訂定，軟質塑膠基板材料朝向無鹵素族的方向設計和開發已是不可避免的趨勢，傳統的透明無色聚醯亞胺高分子材料多以含氟二酸酐單體或二胺單體進行合成，其本身具有高含氟量的特性，除了生產成本較為昂貴之外，在元件加工過程中易發生溶劑阻抗(solvent resistance)不佳的情形而影響到元件製作，且經由燃燒後所釋放出的氫氟酸對於人體與環境有立即性的危害和汙染，因此，降低含氟量可使得透明無色聚醯亞胺高分子材料在未來軟質塑膠基板材料的選用上仍保有一定的競爭力。
本研究將以兩種二酸酐單體3,3',4,4'-Biphenyltetracarboxylic dianhydride (BPDA)、 Bicyclooctanete- tracarboxylic dianhydride (BODA) 與兩種不同的二胺單體3,3'-Diaminodiphenyl sulfone (DDS)、2,2'-Bistrifluoromethyl benzidine (TFMB) 在無水極性非質子溶劑NMP下進行一步驟熱溶液環化法聚縮合反應，其中以BODA脂肪族二酸酐單體取代含氟二酸酐單體以及添加DDS二胺單體以降低其含氟量，透過改變二酸酐單體的比例，合成出不同莫耳比例的低氟透明無色聚醯亞胺高分子並製備成薄膜，再將所合成出的聚醯亞胺高分子及其薄膜進行結構鑑定與性質分析。

In the application of flexible electronic products, such as flexible printed circuits and solar
cells, the trend is moving toward the development of more flexible, highly transparent
designs. Polyimides are a class of high temperature polymers with good mechanical
properties. However, limited solubility and colored film features of polyimides are their
central drawbacks. In order to reach the goal of flexible electronic products in the future,
polyimides have to be soluble and highly transparent.
Taking environmental protection in account, research on halo-free colorless polyimides has
become popular. Conventional colorless polyimides contain a high fluorine content. This not
only increases manufacturing costs, but also leads to the production of hydrofluoric acid,
which is harmful to both the human body and the environment. Therefore, the goal of the
present research is to synthesize low fluoro-containing, transparent, colorless polyimide that
have good solubility and high transparency.
In our research, a series of low fluoro-containing polyimides were synthesized from 3,3',4,4'-
Biphenyltetracarboxylic dianhydride (BPDA) and Bicyclooctanete- tracarboxylic
dianhydride (BODA) used as dianhydride monomers, 3,3'-Diaminodiphenyl sulfone (DDS)
and 2,2'-Bistrifluoromethyl benzidine (TFMB) used as diamine monomers. They were
synthesized using a one-step chemical solution polycondensation method in NMP with a
catalyst (isoquinoline) at 200oC for 24 h. The solubility, thermal properties, mechanical
properties, and optical properties of the polyimides were systematically studied. In this study,
both the transparency and solubility increased with increases in the amount of the BODA
dianhydride monomer.

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