| Summary: | 碩士 === 國立臺北科技大學 === 化學工程研究所 === 99 === This thesis is aimed to synthesize and characterize an aromatic diamine monomer bearing the ether-linked bis(triphenylamine) [O(TPA)2] unit and its derived aromatic polyamides and polyimides. The electrochemical, spectroelectrochemical and electrochromic properties of the polymers have been investigated.
In the first part of this thesis, a new diamine monomer with the O(TPA)2 unit, namely N,N-di(4-aminophenyl)-N'',N''-diphenyl-4,4''-oxydianiline, was synthesized and reacted with various aromatic dicarboxylic acids via the phosphorylation polyamidation reaction leading to a series of novel redox-active aromatic polyamides. These polyamides exhibited inherent viscosities between 0.31 and 0.44 dL/g, and they were readily soluble in polar organic solvents like NMP and DMAc and could be solution-cast into amorphous and flexible films. The polyamides exhibited good thermal stability with glass-transition temperatures in the range of 218-253 oC, 10% weight-loss temperatures in excess of 500 oC and char yields at 800 oC in nitrogen higher than 65%. Cyclic voltammograms of the polyamide films cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at 0.80~0.82 V and 0.96~0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent electrochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and purple oxidized forms at applied potentials ranging from 0 to 1.2 V. Electrochromic devices using these polymers as active materials were also fabricated, and they showed high coloration efficiency, high redox stability, and fast response time.
The second part describes the synthesis and properties of aromatic polyimides on the basis of the diamine monomer with the O(TPA)2 unit in the first part. These polyimides were prepared from the O(TPA)2 diamine monomer and various aromatic tetracarboxylic dianhydrides via a conventional two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical or thermal cyclodehydration. Most of the polyimides were readily soluble in many organic solvents and could be solution-cast into tough and amorphous films. The inherent viscosities of the poly(amic acid) precursors were in the range 0.47-0.88 dL/g. The series of polyimides exhibited excellent thermal stability, with glass-transition temperatures in the range of 227-273 oC and 10% weight-loss temperatures in excess of 550 oC. Cyclic voltammetry studies of the polymer films showed that these polyimides are both p and n dopable and have multicolored electrochromic states.
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