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[摘要]：Three series of new ambipolar polyimides containing aniline derivatives with different degree of 4-methoxyphenyl substituent showing anodically/cathodically electrochromic characteristic were prepared from the polycondensation of three diamine monomers-4,4'-bis[(4-aminophenyl)amino]diphenylamine (3), 4,4'-bis[(4-aminophenyl)amino]-4 ''-methoxytriphenylamine (3'), and 4,4'-bis[4-aminophenyl(4-methoxyphenyl)amino]-4 ''-methoxytriphenylamine (3 '')-with various commercially available tetracarboxylic dianhydrides. In addition to the high glass-transition temperatures (T(g), 246-339 degrees C), thermal stability, and solution processability, the resulting polyimide films exhibited ambipolar electrochromic behavior. The nonconjugated TPA-based polyimides III revealed more stable electrochemical oxidation behavior and better electrochromic reversibility than conjugated DPA-based corresponding polyimides I due to the additional phenyl ring providing the route to stabilize the cation radical formed during oxidation. |
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