- 學位論文
由不對稱的醚二胺衍生的聚醯亞胺與聚醯胺
POLYIMIDES AND POLYAMIDES DERIVED FROM ASYMMETRIC ETHER-DIAMINE
摘要
一種新型具不對稱結構的芳香族二胺5-(4-aminophenoxy)-1- naphthylamine是由5-amino-1-naphthol與4-chloronitrobenzene於dimethylformamide (DMF)中，及K2CO3共存下進行芳香親核取代 反應，隨後再進行還原反應而製得。一系列新型具有醚鏈及不對稱結構的聚醯亞胺是利用上述製得之二胺與一系列市售之芳香族二酐經由二步驟聚合法所製得。第一步驟製得之聚醯胺酸前驅物的固有黏度介於1.21~1.99 dL/g之間，它們均可熱轉化成透明、具撓曲性的及強韌的聚醯亞胺薄膜。這些聚醯亞胺的玻璃轉移溫度及軟化溫度分別介於307~336 oC和299~344 oC之間，它們在氮氣或空氣中皆在520 oC以上才會產生明顯的熱分解。為了性質比較，兩系列由具對稱結構二胺如1,5-diamino- naphthalene和1,5-bis(4-aminophenoxy)naphthalene所衍生之聚醯亞胺的 合成與性質亦在本研究中加以探討。 此外，另一系列新型含醚鏈及不對稱的芳香族聚醯胺亦是利用前述的二胺和一系列市售的芳香族二羧酸進行直接磷酸化聚縮合反應而製得，這些聚醯胺溶液的固有黏度介於0.74~1.36 dL/g之間。除了以結構較剛硬的二羧酸如4,4’-biphenyldicarboxylic acid所製得的聚醯胺具有較高的結晶性且不易溶於有機溶劑之外，其餘的聚醯胺皆為非結晶性的材料並易溶於大部分的有機溶劑並可由其溶液鑄成透明且具可撓曲性的強韌薄膜。這些聚醯胺的玻璃轉移溫度介於222~288 oC，而軟化溫度則介於222~279 oC。在氮氣及空氣中重量損失達5 %的熱分解溫度皆在400 oC以上，顯示具有良好的熱安定性。與由1,5-diaminonaphthalene 衍生之主鏈具有對稱結構的聚醯胺比較，這些聚醯胺具有較低的結晶 性、玻璃轉移溫度及軟化溫度，並且擁有較佳的溶解性。
並列摘要
A new aromatic asymmetrical ether-diamine, 5-(4-aminophenoxy)-1- naphthylamine, was synthesized through the nucleophilic displacement of 4-chloronitrobenzene with the potassium salt of 5-amino-1-naphthol in dimethylformamide, followed by hydrazine palladium-catalyzed reduction. A series of novel aromatic polyimides containing asymmetrical diaryl ether segment were prepared from the diamine with various aromatic dianhydrides via a conventional two-step thermal or chemical imidization method. The poly(amic acid) precursors had inherent viscosity of 1.21~1.99 dL/g, and all of them could be cast and thermally converted into transparent, flexible, and tough polyimide films. The polyimides derived from less stiff dianhydrides generally displayed a higher solubility. The glass-transition temperatures of these polyimides were recorded between 307~336 oC by differential scanning calorimetery and the softening temperatures of the polymer films were in the range of 299~344 oC according to thermomechanical analysis. The polyimides showed insignificant decomposition before 520 oC in air or nitrogen. For a comparative study, two series of analogous polyimides based on symmetrical diamines such as 1,5-diaminonaphthalene and 1,5-bis(4- aminophenoxy)naphthalene were also prepared and characterized. A series of novel aromatic polyamides containing asymmetrical diaryl ether structure were synthesized by the direct phosphorylation polycondensation of 5-(4-aminophenoxy)-1-naphthylamine with various dicarboxylic acids. These polymers were produced in high yields and inherent viscosity (0.74~1.36 dL/g). The polyamide derived from the rigid diacid such as 4,4’-biphenyldicarboxylic acid was semicrystalline and insoluble in most organic solvents. The other polyamides were amorphous and organosoluble and afforded flexible and tough films via solution casting. These polyamides showed glass-transition temperatures between 222~288 oC and softening temperature between 222~279 oC. Decomposition temperature (Td) for 5 % weight loss all occurred above 400 oC in both nitrogen and air atmospheres. All the asymmetrical polyamides displayed relatively lower crystallinity, Tg and Td values, and better solubility than the corresponding analogues derived from symmetrical 1,5-diaminonaphthalene.