| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 99 === Three series of new polyamides based on triphenylamine showing anodically electrochromic characteristic were synthesized from the polycondensation reaction of three diamine monomers, 2,6-bis(N,N-(4-aminophenyl-4’-methoxyphenyl)amino) naphthalene(2),
1,6-bis(N,N-(4-aminophenyl-4’-methoxyphenyl)amino)pyrene(5), and
N,N’-bis(4-methoxyplenyl)-N,N’-bis[4-(4-aminophenyl-4’-
methoxyphenylamino)phenyl]-p-phenylenediamine(8) with various commercially available aromatic dicarboxylic acids, respectively. All the polyamides were amorphous with good solubility in many organic solvents, such as N-methyl-2-prrolidinone(NMP) and N,N-dimethyl-acetamide(DMAC). These aromatic polyamides had good thermal stability associated with their high glass-transition temperatures(204~308℃), and 10% weight-loss temperatures in excess of 420℃.
The polyamides (3) derived from the diamine 2 showed reversible electrochemical oxidation accompanied by strong color change with high coloration efficiency(CE), high contrast ratio, and rapid switching time. The optical transmittance change (△T%) at 888 nm between the neutral state and the fully oxidized state is up to 98.9%, and the coloration efficiency is as high as ca. 313 cm2/C.
The polyamides 6 derived from the diamine 5 showed reversible electrochemical oxidation accompanied by strong color change with high contrast ratio, and rapid switching time. The optical transmittance change (△T%) at 1031 nm between the neutral state and the fully oxidized state is up to 89%. In addition, the dilute NMP solutions of these polyamides exhibited fluorescence maxima around 536~541 nm with quantum yields up to 40.6%.
The polyamides 9 derived from the diamine 8 showed reversible electrochemical oxidation with high contrast ratio both in the visible range and NIR region, which also exhibited high coloration efficiency, and high stability for long-term electrochromic operation. At the first oxidation stage, the polyamide film 9a revealed high coloration efficiency in visible(CE=272 cm2/C) and NIR(CE=305 cm2/C) region with reversible electrochemical cycling stability(over 14000 times within 4.32% loss relative to its initial CE). As the dication radical form of second oxidation stage, the polymer film still exhibited excellent electrochromic/electroactive stability(more than 8000 cyclic swithes) with enhaced contrast ration of 87.8%.
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