| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 92 === A series of new polyimides, containing pendant long alkyl side chain groups were prepared via the solution condensation of aromatic diahydrides with 2,2’-bis(2-hexloxyphenoxy)-5,5’-diaminobiphenyl, 2,2’-bis(3-octadecyloxyphenoxy)-5,5’-diaminobiphenyl, and 2,2’-bis(2-octadecyloxyphenoxy)-5,5’-diaminobiphenyl. The inherent viscosities, solubility properties and thermal properties of the polyimides were investigated.
First, the poly(amic acid)s derived from 2,2’-bis(3-octadecyloxyphenoxy)-5,5’-diaminobiphenyl, had inherent of 0.15~0.21 dL/g. The DMA analysis reveals that the glass transition temperatures ranged from 141~180℃. In addition, the temperatures of 10% weight loss in nitrogen and the air ranged on 405~427℃ and 338~425℃, respectively. The polyimides 10 showed lower solubility as compared to the analogous polyimides 8.
Second, a series of polyimides were prepared by reaction of long alkyl-based diamines, 2,2’-bis(2-hexloxyphenoxy)-5,5’-diaminobiphenyl with various aromatic tetracarboxylic dianhydride. The polymer were prepared with moderate to high inherent viscosities (0.73~1.26 dL/g). The obtained polyimides were readily soluble in NMP, DMAc, THF, and cyclohexanone and gave flexible and tough films via solvent casting. These polyimides showed glass transition temperature in the range of 139~174℃ (by DSC) . Decomposition temperatures for 10% weight loss in nitrogen and the air ranged on 413~423℃ and 370~417℃, respectively.
Third, a series of polyimides were prepared by reaction of long alkyl-based diamines, 2,2’-bis(2-octadecyloxyphenoxy)-5,5’-diaminobiphenyl with various aromatic tetracarboxylic dianhydride. The polymers were prepared with moderate to low inherent viscosities (0.10~0.16 dL/g). The obtained polyimides were readily soluble in NMP, DMAc, THF, and cyclohexanone and gave inflexible film.
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