由含三氟甲基之芳香族二醚二胺衍生之無色含氟聚醯亞胺、可溶性聚萘醯亞胺、及聚醯亞胺/二氧化矽混成材料之合成及其性質之研究

SYNTHESIS AND CHARACTERIZATION OF COLORLESS FLUORINATED POLYIMIDES, ORGANOSOLUBLE POLYNAPHTHALIMIDES AND POLYIMIDE/SILICA HYBRIDS DERIVED FROM AROMATIC BIS(ETHER AMINE)S BEARING TRIFLUOROMETHYL GROUPS

蘇育央(Yu-Yang Su)

指導教授 ： 蕭勝輝 ； 楊金平

大同大學/工程學院/化學工程學系所/博士(2007年)

摘要

本論文在探討由側鏈含三氟甲基之芳香族之二醚二胺所衍生之無色含氟聚醯亞胺、可溶性聚萘醯亞胺及聚醯亞胺/二氧化矽混成材料之研究及其性質。
三系列無色透明及具有可溶性與良好熱性質之含氟芳香族聚醯亞胺(3A, 3B, 3C)是分別由2,3,3’,4’-biphenyltetracarboxylic dianhydride (a-BPDA)、2,5-bis(3,4-dicarboxyphenoxy)-tert-butylbenzene dianhydride [bis(ether anhydride) B]，以及3,3-bis[4-(3,4-dicarboxyphenoxy)phenyl]phthalide dianhydride [bis(ether anhydride) C]與多種含三氟甲基之芳香族二醚二胺經由二步驟反應法而製得，即先在N,N-dimethylacetamide (DMAc)中開環聚加成為poly(amic acid)s後，再以熱閉環或化學閉環法生成新型聚醯亞胺[polyimides (PI)]。這些含氟聚醯亞胺薄膜皆於所測試溶劑中具有優異之有機可溶性，且薄膜皆具有高透光度、低著色性及優良的機械與熱性質。此外，相對應不含氟之芳香族聚醯亞胺或異構物亦被合成製備，並與含氟芳香族聚醯亞胺做物性上比較。由研究結果可發現含氟之聚醯亞胺確實較不含氟之芳香族聚醯亞胺具有更高的溶解性、高透光性，低著色性，及較低的介電常數及吸濕性，且維持優異的熱與機械性質。
此外，一系列可溶性聚萘醯亞胺 [Polynaphthalimides (PNI)]是以苯甲酸為觸媒，經由萘環二酐1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA)與二種芳香族二胺(其中之ㄧ為3,3-bis-[4-(4-aminophenoxy)phenyl]phthalide作為增加聚合物溶解性之組成)在高溫下聚縮合而成。這些PNIs可由m-cresol溶劑鑄膜得透明且具有良好機械性之薄膜，抗張強度在76-103 MPa之間。然而對於有機溶解性的改善卻是有限的，僅部份co-PNIs於1-methy-2-pyrrolidone和m-cresol溶劑中為5–10wt%可溶，而在DMAc及Pyridine溶劑中呈現微溶，其餘之測試溶劑則呈現難溶現象。為改善聚萘醯亞胺之溶解性及增加加工性，我們將以側鏈含三氟甲基之芳香族二醚二胺取代一般芳香族二胺，以製備有機可溶性含氟聚萘醯亞胺PNI-2。這些含氟聚萘醯亞胺顯示優異的溶解性，在amide型極性溶劑、pyridine 或m-cresol溶劑等中為10%可溶，且可由DMAc溶劑鑄得強韌之透明薄膜，它們具有93-134 MPa之抗張強度。這些聚萘醯亞胺不僅溶解性明顯改善，且其熱穩定性亦有所提升。
最後，一系列polyimide/silica (PI/silica)混成薄膜是由含氟之二醚二胺4,4’-bis(4-amino-2-trifluoromethylphenoxy)biphenyl與市售芳香族二酐先製備poly(amic acid)s後，加入以3-aminopropyltrimethoxysilane (APrTMOS)為偶合劑，使合成具有propyltrimethoxysliane末端之poly(amic acid)s，然後再加入tetramethoxysilane (TMOS)/H2O進行sol-gel 反應後鑄膜及醯亞胺化得一系列含氟之PI/silica-3混成材料。這些混成材料為色淡、高透光性且兼具良好熱性質之強韌薄膜。此外，這些含氟之PI/silica比一般不含氟之PI/silica具有高透明度、低著色性。且混成後之polyimide/silica顯示比未混成silica之純polyimide具有較低折射率及雙折射率。

關鍵字

無色聚醯亞胺、可溶性聚萘醯亞胺、聚醯亞胺/二氧化矽、三氟甲基之芳香族二醚二胺

並列摘要

This dissertation deals with the synthesis and properties of colorless polyimides, organosoluble polynaphthalimides, and fluorine-containing polyimide/silica composite films based on trifluoromethyl-substituted bis(ether amine).
Three series of novel, colorless polyimides (3A, 3B, 3C) were synthesized from trifluoromethyl-substituted bis(ether amine)s with 2,3,3’,4’-biphenyltetracarboxylic dianhydride (a-BPDA), 2,5-bis(3,4-dicarboxyphenoxy)-tert-butylbenzene dianhydride [bis(ether anhydride) B], and 3,3-bis[4-(3,4-dicarboxyphenoxy)phenyl]phthalide dianhydride [bis(ether anhydride) C], respectively, via two-step method with thermal or chemical imidization of poly(amic acid)s. These fluorinated polyimide films showed excellent solubility in a variety of organic solvents, high optical transparency, low color intensity, and good tensile property as well as high thermal stability. Besides, the analogous non-fluorinated or isomeric polyimides were also prepared and characterized. The fluorinated polyimides were apparently characterized by higher solubility, lighter color, and lower dielectric constants and moisture absorption than their analogous non-fluorinated polyimides.
In addition, a series of polynaphthalimides (PNIs), co-PNI-3, were prepared from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with common aromatic diamines and 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide, which was used as a solubility-enhancing agent, via a one stage process with high-temperature condensation. These PNIs could afford transparent and tough films by m-cresol solvent casting with a tensile strength of 76-103 MPa. However, their solubility was limited, only some of them were soluble in 1-methy-2-pyrrolidone and m-cresol at 5–10 wt %. In order to improve the solubility of PNIs, we used the trifluoromethyl-substituted aromatic bis(ether amine)s as the diamine monomers to prepare a series of fluorinated PNI-2a-g. This series of PNIs are highly organosoluble and can be solution-cast into transparent and tough films with a tensile strength ranging from 93 to 134 MPa. The softening temperature (Ts) of these PNIs were in the range of 234-331 °C, and the 10% weight-loss temperatures were above 528 °C in nitrogen or air, with more than 50% char yield at 800 °C in nitrogen.
Moreover, a series of polyimide precursors, poly(amic acid)s, containing propyltrimethoxysliane at two chain ends were prepared from 4,4’-bis(4-amino-2-trifluoromethylphenoxy)biphenyl with six commercially available dianhydrides, followed by end-capping with 3-aminopropyltrimethoxysilane (APrTMOS). A new class of fluorine-containing polyimide/silica composite films (PI/silica-3) with chemical bonds between the fluorinated polyimide backbone and the silica network has been synthesized from the APrTMOS-terminated precursors with tetramethoxysilane (TMOS) via the sol-gel process and thermal cyclodehydration. The resultant hybrid films were light-colored, flexible and tough and had high levels of thermal stability. Besides, the hybrid films of the fluorinated PI/silica-3 series showed a higher transparency and less color intensity as compared to the non-fluorinated PI/silica-3’ analogs. They also revealed a lower refraction index and birefringence than pure polyimides (PI-4).

並列關鍵字

colorless polyimides ； polynaphthalimides ； polyimide/silica hybrids ； aromatic bis(ether amine)s ； trifluoromethyl groups ； solubility

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